Rice cultivar taggart

ABSTRACT

A rice cultivar designated Taggart is disclosed. The invention relates to the seeds of rice cultivar Taggart, to the plants of rice Taggart, to methods for producing a rice plant produced by crossing the cultivar Taggart with itself or another rice variety, and to methods for controlling weeds in the vicinity of plants of rice cultivar Taggart, which comprises increased resistance to acetohydroxyacid synthase-inhibiting herbicides. The invention further relates to hybrid rice seeds and plants produced by crossing the cultivar Taggart with another rice cultivar.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinctive rice cultivar, designated Taggart. All publications cited in this application are herein incorporated by reference.

Rice is an ancient agricultural crop and is today one of the principal food crops of the world. There are two cultivated species of rice: Oryza sativa L., the Asian rice, and O. glaberrima Steud., the African rice. O. sativa L. constitutes virtually all of the world's cultivated rice and is the species grown in the United States. Three major rice producing regions exist in the United States: the Mississippi Delta (Arkansas, Mississippi, northeast Louisiana, southeast Missouri), the Gulf Coast (southwest Louisiana, southeast Texas), and the Central Valleys of California.

Rice is a semi-aquatic crop that benefits from flooded soil conditions during part or all of the growing season. In the United States, rice is grown on flooded soils to optimize grain yields. Heavy clay soils or silt loam soils with hard pan layers about 30 cm below the surface are typical rice-producing soils because they minimize water losses from soil percolation. Rice production in the United States can be broadly categorized as either dry-seeded or water-seeded. In the dry-seeded system, rice is sown into a well-prepared seed bed with a grain drill or by broadcasting the seed and incorporating it with a disk or harrow. Moisture for seed germination is from irrigation or rainfall. Another method of planting by the dry-seeded system is to broadcast the seed by airplane into a flooded field, then promptly drain the water from the field. For the dry-seeded system, when the plants have reached sufficient size (four- to five-leaf stage), a shallow permanent flood of water 5 cm to 16 cm deep is applied to the field for the remainder of the crop season.

In the water-seeded system, rice seed is soaked for 12 to 36 hours to initiate germination, and the seed is broadcast by airplane into a flooded field. The seedlings emerge through a shallow flood, or the water may be drained from the field for a short period of time to enhance seedling establishment. A shallow flood is maintained until the rice approaches maturity. For both the dry-seeded and water-seeded production systems, the fields are drained when the crop is mature, and the rice is harvested 2 to 3 weeks later with large combines. In rice breeding programs, breeders try to employ the production systems predominant in their respective region. Thus, a drill-seeded breeding nursery is used by breeders in a region where rice is drill-seeded and a water-seeded nursery is used in regions where water-seeding is important.

Rice in the United States is classified into three primary market types by grain size, shape, and chemical composition of the endosperm: long-grain, medium grain and short-grain. Typical U.S. long-grain cultivars cook dry and fluffy when steamed or boiled, whereas medium- and short-grain cultivars cook moist and sticky. Long-grain cultivars have been traditionally grown in the southern states and generally receive higher market prices.

Although specific breeding objectives vary somewhat in the different regions, increasing yield is a primary objective in all programs. Grain yield of rice is determined by the number of panicdes per unit area, the number of fertile florets per panicle, and grain weight per floret. Increases in any or all of these yield components may provide a mechanism to obtain higher yields. Heritable variation exists for all of these components, and breeders may directly or indirectly select for increases in any of them.

There are numerous steps in the development of any novel, desirable plant germplasm. Plant breeding begins with the analysis and definition of problems and weaknesses of the current germplasm, the establishment of program goals, and the definition of specific breeding objectives. The next step is selection of germplasm that possess the traits to meet the program goals. The goal is to combine in a single variety an improved combination of desirable traits from the parental germplasm. These important traits may include higher seed yield, resistance to diseases and insects, better stems and roots, tolerance to low temperatures, and better agronomic characteristics on grain quality.

Choice of breeding or selection methods depends on the mode of plant reproduction, the heritability of the trait(s) being improved, and the type of cultivar used commercially (e.g., F₁ hybrid cultivar, pureline cultivar, etc.). For highly heritable traits, a choice of superior individual plants evaluated at a single location will be effective, whereas for traits with low heritability, selection should be based on mean values obtained from replicated evaluations of families of related plants. Popular selection methods commonly include pedigree selection, modified pedigree selection, mass selection, and recurrent selection, or a combination of these methods.

The complexity of inheritance influences choice of the breeding method. Backcross breeding is used to transfer one or a few favorable genes for a highly heritable trait into a desirable cultivar. This approach has been used extensively for breeding disease-resistant cultivars. Various recurrent selection techniques are used to improve quantitatively inherited traits controlled by numerous genes. The use of recurrent selection in self-pollinating crops depends on the ease of pollination, the frequency of successful hybrids from each pollination, and the number of hybrid offspring from each successful cross.

Each breeding program should include a periodic, objective evaluation of the efficiency of the breeding procedure. Evaluation criteria vary depending on the goal and objectives, but should include gain from selection per year based on comparisons to an appropriate standard, overall value of the advanced breeding lines, and number of successful cultivars produced per unit of input (e.g., per year, per dollar expended, etc.).

Promising advanced breeding lines are thoroughly tested and compared to appropriate standards in environments representative of the commercial target area(s) for three or more years. The best lines are candidates for new commercial cultivars; those still deficient in a few traits may be used as parents to produce new populations for further selection.

These processes, which lead to the final step of marketing and distribution, usually take from 8 to 12 years from the time the first cross is made and may rely on the development of improved breeding lines as precursors. Therefore, development of new cultivars is a time-consuming process that requires precise forward planning, efficient use of resources, and a minimum of changes in direction.

A most difficult task is the identification of individuals that are genetically superior, because for most traits the true genotypic value is masked by other confounding plant traits or environmental factors. One method of identifying a superior plant is to observe its performance relative to other experimental plants and to a widely grown standard cultivar. If a single observation is inconclusive, replicated observations provide a better estimate of its genetic worth.

The goal of rice plant breeding is to develop new, unique and superior rice cultivars and hybrids. The breeder initially selects and crosses two or more parental lines, followed by self-pollination and selection, producing many new genetic combinations. The breeder can theoretically generate billions of different genetic combinations via crossing, selfing, and mutations. The breeder has no direct control at the cellular level. Therefore, two breeders will never develop the same line, or even very similar lines, having the same rice traits.

Each year, the plant breeder selects the germplasm to advance to the next generation. This germplasm is grown under unique and different geographical, climatic and soil conditions, and further selections are then made, during and at the end of the growing season. The cultivars which are developed are unpredictable. This unpredictability is because the breeder's selection occurs in unique environments, with no control at the DNA level (using conventional breeding procedures), and with millions of different possible genetic combinations being generated. A breeder of ordinary skill in the art cannot predict the final resulting lines he develops, except possibly in a very gross and general fashion. The same breeder cannot produce the same cultivar twice by using the exact same original parents and the same selection techniques. This unpredictability results in the expenditure of large amounts of research monies to develop superior new rice cultivars.

The development of new rice cultivars requires the development and selection of rice varieties, the crossing of these varieties and selection of superior hybrid crosses. The hybrid seed is produced by manual crosses between selected male-fertile parents or by using male sterility systems. These hybrids are selected for certain single gene traits such as semi-dwarf plant type, pubescence, awns, and apiculus color which indicate that the seed is truly a hybrid. Additional data on parental lines, as well as the phenotype of the hybrid, influence the breeder's decision whether to continue with the specific hybrid cross.

Pedigree breeding and recurrent selection breeding methods are used to develop cultivars from breeding populations. Breeding programs combine desirable traits from two or more cultivars or various broad-based sources into breeding pools from which cultivars are developed by selfing and selection of desired phenotypes. The new cultivars are evaluated to determine which have commercial potential.

Pedigree breeding is used commonly for the improvement of self-pollinating crops. Two parents which possess favorable, complementary traits are crossed to produce an F₁. An F₂ population is produced by selfing one or several F₁'s. Selection of the best individuals may begin in the F₂ population; then, beginning in the F₃, the best individuals in the best families are selected. Replicated testing of families can begin in the F₄ generation to improve the effectiveness of selection for traits with low heritability. At an advanced stage of inbreeding (i.e., F₆ and F₇), the best lines or mixtures of phenotypically similar lines are tested for potential release as new cultivars.

Mass and recurrent selections can be used to improve populations of either self- or cross-pollinating crops. A genetically variable population of heterozygous individuals is either identified or created by intercrossing several different parents. The best plants are selected based on individual superiority, outstanding progeny, or excellent combining ability. The selected plants are intercrossed to produce a new population in which further cycles of selection are continued.

Backcross breeding has been used to transfer genes for a simply inherited, highly heritable trait into a desirable homozygous cultivar or inbred line which is the recurrent parent. The source of the trait to be transferred is called the donor parent. The resulting plant is expected to have the attributes of the recurrent parent (e.g., cultivar) and the desirable trait transferred from the donor parent. After the initial cross, individuals possessing the phenotype of the donor parent are selected and repeatedly crossed (backcrossed) to the recurrent parent. The resulting plant is expected to have the attributes of the recurrent parent (e.g., cultivar) and the desirable trait transferred from the donor parent.

The single-seed descent procedure in the strict sense refers to planting a segregating population, harvesting a sample of one seed per plant, and using the one seed sample to plant the next generation. When the population has been advanced from the F₂ to the desired level of inbreeding, the plants from which lines are derived will each trace to different F₂ individuals. The number of plants in a population declines each generation due to failure of some seeds to germinate or some plants to produce at least one seed. As a result, not all of the F₂ plants originally sampled in the population will be represented by a progeny when generation advance is completed.

In a multiple-seed procedure, rice breeders commonly harvest one or more seeds from each plant in a population and thresh them together to form a bulk. Part of the bulk is used to plant the next generation and part is put in reserve. The procedure has been referred to as modified single-seed descent or the pod-bulk technique.

The multiple-seed procedure has been used to save labor at harvest. It is considerably faster to thresh panicles with a machine than to remove one seed from each by hand for the single-seed procedure. The multiple-seed procedure also makes it possible to plant the same number of seeds of a population each generation of inbreeding. Enough seeds are harvested to make up for those plants that did not germinate or produce seed.

Descriptions of other breeding methods that are commonly used for different traits and crops can be found in one of several reference books (e.g., Allard, 1960; Simmonds, 1979; Sneep, et. al, 1979; Fehr, 1987).

Proper testing should detect any major faults and establish the level of superiority or improvement over current cultivars. In addition to showing superior performance, there must be a demand for a new cultivar that is compatible with industry standards or which creates a new market. The introduction of a new cultivar will incur additional costs to the seed producer, the grower, processor and consumer; for special advertising and marketing, altered seed and commercial production practices, and new product utilization. The testing preceding release of a new cultivar should take into consideration research and development costs as well as technical superiority of the final cultivar. For seed-propagated cultivars, it must be feasible to produce seed easily and economically.

Rice, Oryza sativa L., is an important and valuable field crop. Thus, a continuing goal of plant breeders is to develop stable, high yielding rice cultivars that are agronomically sound. The reasons for this goal are obviously to maximize the amount of grain produced on the land used and to supply food for both animals and humans. To accomplish this goal, the rice breeder must select and develop rice plants that have the traits that result in superior cultivars.

The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related are will become apparent to those of skill in the art upon a reading of the specification.

SUMMARY OF THE INVENTION

The following embodiments and aspects thereof are described in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, no limiting in scope. In various embodiments, one or more of the above described problems have been reduced or eliminated, while other embodiments are directed to other improvements.

According to the invention, there is provided a novel rice cultivar designated Taggart. This invention thus relates to the seeds of rice cultivar Taggart, to the plants of rice Taggart, and to methods for producing a rice plant produced by crossing rice Taggart with itself or another rice line.

Thus, any such methods using rice variety Taggart are part of this invention: selfing, backcrosses, hybrid production, crosses to populations, and the like. All plants produced using rice variety Taggart as a parent are within the scope of this invention. Advantageously, the rice variety could be used in crosses with other, different, rice plants to produce first generation (F₁) rice hybrid seeds and plants with superior characteristics.

In another aspect, the present invention provides for single gene converted plants of Taggart. The single transferred gene may preferably be a dominant or recessive allele. Preferably, the single transferred gene will confer such traits as herbicide resistance, insect resistance, resistance for bacterial, fungal, or viral disease, male fertility, male sterility, enhanced nutritional quality, and industrial usage. The single gene may be a naturally occurring rice gene or a transgene introduced through genetic engineering techniques.

In another aspect, the present invention provides regenerable cells for use in tissue culture of rice plant Taggart. The tissue culture will preferably be capable of regenerating plants having the physiological and morphological characteristics of the foregoing rice plant, and of regenerating plants having substantially the same genotype as the foregoing rice plant. Preferably, the regenerable cells in such tissue cultures will be embryos, protoplasts, meristematic cells, callus, pollen, leaves, anthers, pistils, root tips, flowers, seeds, panicles, or stems. Still further, the present invention provides rice plants regenerated from the tissue cultures of the invention.

In one aspect, the present invention provides methods for controlling weeds or undesired vegetation in the vicinity of a plant of rice cultivar Taggart. One method comprises applying an effective amount of an acetohydroxyacid synthase (AHAS)-inhibiting herbicide, particularly an imidazolinone herbicide, to the weeds and to a plant of rice cultivar Taggart. Another method comprises contacting a seed of rice cultivar Taggart before sowing and/or after pregermination with an effective amount of an AHAS-inhibiting herbicide, particularly an imidazolinone herbicide. The present invention further provides seeds of rice cultivar Taggart treated with an effective amount of an AHAS-inhibiting herbicide, particularly an imidazolinone herbicide.

In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by study of the following descriptions.

DEFINITIONS

In the description and tables which follow, a number of terms are used. In order to provide a clear and consistent understanding of the specification and claims, including the scope to be given such terms, the following definitions are provided:

Alkali Spreading Value. Indicator of gelatinization temperature and an index that measures the extent of disintegration of milled rice kernel in contact with dilute alkali solution. Standard long grains have 3 to 5 Alkali Spreading Value (intermediate gelatinization temperature).

Allele. Allele is any of one or more alternative forms of a gene, all of which relate to one trait or characteristic. In a diploid cell or organism, the two alleles of a given gene occupy corresponding loci on a pair of homologous chromosomes.

Apparent Amylose Percent. The most important grain characteristic that describes cooking behavior in each grain class, or type, i.e., long, medium and short grain. The percentage of the endosperm starch of milled rice that is amylose. Standard long grains contain 20 to 23% amylose. Rexmont type long grains contain 24 to 25% amylose. Short and medium grains contain 16 to 19% amylose. Waxy rice contains 0% amylose. Amylose values will vary over environments.

Backcrossing. Backcrossing is a process in which a breeder repeatedly crosses hybrid progeny back to one of the parents, for example, a first generation hybrid F₁ with one of the parental genotypes of the F₁ hybrid.

Days to 50% heading. Average number of days from emergence to the day when 50% of all panicles are exerted at least partially through the leaf sheath. A measure of maturity.

Essentially all the Physiological and morphological characteristics. A plant having essentially all the physiological and morphological characteristics means a plant having the physiological and morphological characteristics of the cultivar, except for the characteristics derived from the converted gene.

Gene Converted (Conversion). Gene converted (conversion) plant refers to plants which are developed by backcrossing, genetic engineering or mutation wherein essentially all of the desired morphological and physiological characteristics of a variety are recovered in addition to the one or more traits transferred into the variety via the backcrossing technique, genetic engineering, or mutation.

Grain Length (L). Length of a rice grain is measured in millimeters.

Grain Width (W). Width of a rice grain is measured in millimeters.

Grain Yield. Grain yield is measured in pounds per acre and at 12.0% moisture. Grain yield of rice is determined by the number of panicles per unit area, the number of fertile florets per panicle, and grain weight per floret.

Harvest Moisture. The percent of moisture of the grain when harvested.

Length/Width (L/W) Ratio. This ratio is determined by dividing the average length (L) by the average width (W).

Lodging Resistance (also called Straw Strength). Lodging is measured as a subjective rating and is percentage of the plant stems leaning or fallen completely to the ground before harvest. Relative scale.

1000 Grain Wt. The weight of 1000 rice grains as measured in grams.

Plant Height. Plant height in centimeters is taken from soil surface to the tip of the extended panicle at harvest.

Peak Viscosity. The maximum viscosity attained during heating when a standardized instrument-specific protocol is applied to a defined rice flour-water slurry.

Trough Viscosity. The minimum viscosity after the peak, normally occurring when the sample starts to cool.

Final Viscosity. Viscosity at the end of the test or cold paste.

Breakdown. The peak viscosity minus the hot paste viscosity.

Setback. Setback 1 is the final viscosity minus trough viscosity. Setback 2 is the final viscosity minus peak viscosity.

RVA Viscosity. Rapid Visco Analyzer is a widely used laboratory instrument to examine paste viscosity, or thickening ability of milled rice during the cooking process.

Hot Paste Viscosity. Viscosity measure of rice flour/water slurry after being heated to 95° C. Lower values indicate softer and stickier cooking types of rice.

Cool Paste Viscosity. Viscosity measure of rice flour/water slurry after being heated to 95° C. and uniformly cooled to 50° C. (American Association of Cereal Chemist). Values less than 200 for cool paste indicate softer cooking types of rice.

Quantitative Trait Loci (QTL). Quantitative trait loci (QTL) refer to genetic loci that control to some degree numerically representable traits that are usually continuously distributed.

Regeneration. Regeneration refers to the development of a plant from tissue culture.

DETAILED DESCRIPTION OF THE INVENTION

Rice cultivar Taggart originated from a cross made at Stuttgart, Ark. in 2000. Rice cultivar Taggart is a very high-yielding, mid-season, long-grain, rice cultivar with maturity similar to rice cultivar ‘Drew.’ Plants of rice cultivar Taggart have erect culms, olive-green erect leaves and glabrous lemma, palea, and leaf blades. The lemma and palea are straw colored with red and purple apiculi, many of which fade to straw at maturity and some short tip awns on the lemma when grown under high fertility. Kernels of rice cultivar are large, with an individual milled kernel weight of 20.1.

Rice cultivar Taggart has a straw strength similar to rice cultivars ‘Francis’ and ‘Wells’ which is an indicator of lodging resistance. On a relative straw strength scale (0=very strong straw, 9=very weak straw), rice cultivars Taggart, ‘Francis’, ‘Wells’, ‘LaGrue’, ‘Drew’, ‘Cybonnet’, and ‘Cocodrie’ rated 3, 3, 3, 4, 4, 2, and 2, respectively.

Rough rice grain yields of rice cultivar Taggart have consistently ranked as one of the highest in the Arkansas Rice Performance Trials (ARPT) being equal to the yields of rice cultivars ‘Francis’, ‘LaGrue’, and ‘Wells’ in all three years. In 16 ARPT tests conducted from 2006 to 2008, rice cultivars Taggart, ‘Francis’, ‘Wells’, ‘LaGrue’, ‘Cybonnet’, ‘Cocodrie’, and ‘Drew’ averaged yields of 9425, 9526, 9274, 9173, 8467, 7963, and 8114 kg ha⁻¹ (120 g kg⁻¹ (12%) moisture), respectively. Data from the Uniform Regional Rice Nursery (URRN) conducted at Louisiana, Mississippi, and Texas from 2006 to 2008 and Arkansas and Missouri from 2007 to 2008, showed that rice cultivar Taggart had an average grain yield of 10,433 kg ha⁻¹ and compared favorably with grain yields of ‘Francis’, ‘Wells’, ‘Cybonnet’, and ‘Cocodrie’ at 10,181, 10,030, 9274, 9727 kg ha⁻¹, respectively. Milling yields (mg g⁻¹ whole kernel:mg g⁻¹ total milled rice) at 120 mg g⁻¹ moisture from the ARPT from 2006 to 2008 averaged 570:710, 580:690, 540:710, 560:700, 610:710, 620:710, and 580:700 for rice cultivars Taggart, ‘Francis’, ‘Wells’, ‘LaGrue’, ‘Cybonnet’, ‘Cocodrie’, and ‘Drew’, respectively. Milling yields for the URRN during the same period of time, 2006 to 2008, averaged 560:710, 570:680, 560:690, 640:710, and 580:700, for rice cultivars Taggart, ‘Francis’, ‘Wells’, ‘Cybonnet’, and ‘Cocodrie’, respectively.

The cultivar has shown uniformity and stability as described in the following variety description information. It has been self-pollinated a sufficient number of generations with careful attention to uniformity of plant type. The variety has been increased with continued observation for uniformity.

Rice cultivar Taggart has the following morphologic and other characteristics (based primarily on data collected at Stuttgart, Ark.).

TABLE 1 VARIETY DESCRIPTION INFORMATION Plant: Grain type: Long Days to maturity (50% heading): About 93 Plant height: Average is 113 cm Plant color (at booting): Olive-green Culm: Angle (degrees from perpendicular after flowering): Erect (less than 30°) Flag Leaf (after heading): Pubescence: Glabrous Leaf angle (after heading): Erect to Intermediate Blade color: Olive-green Panicle: Length: 25.6 cm (range is 17.2 cm to 30.2 cm) Type: Intermediate Exsertion (near maturity): Moderately-well Axis: Droopy Shattering: Low (1-5%) Grain (Spikelet): Awns (after full heading): Absent but can have tip awns at high fertility Apiculus color (at maturity): Red and purple often fading to straw (have some seeds which fade at maturity) Stigma color: White Lemma and palea color (at maturity): Straw Lemma and palea pubescence: Glabrous Grain (Seed): Seed coat (bran) color: Light-brown Endosperm type: Non-glutinous Scent: Non-aromatic Shape class (length/width ratio): Paddy: Long (3.4:1 and more) Brown: Long (3.1:1 and more) Milled: Long (3.0:1 and more) Size: Approximately 20.5 g/1000 seed milled rice (range is 19.0 to 22.0 g/1000 seed milled rice) Starch amylose content: 22.3 g kg⁻¹ Alkali spreading value: 3 to 5 (17 g kg⁻¹ KOH Solution) Gelatinization temperature type: Intermediate (70° C. to 75° C.) Disease Resistance: Rice Blast (Pyricularia grisea (Cooke) Sacc.): Susceptible to races IB-1, IB-33, IB-49, IC-17, IE-1, and IE-1K Leaf Smut (Entyloma oryzae Syd. and P. Syd.): Moderately resistant Brown Spot (Cochliobolus miyabeanus (Ito & Kuribayashi in Ito) Drechs. ex Dastur): Resistant Kernel Smut (Tilletia barclayana (Bref.) Sacc. and Syd. in Sacc.): Susceptible Stem Rot (Sclerotium oryzae): Susceptible Sheath Blight (Rhizoctonia solani Kühn): Moderately susceptible False Smut (Ustilaginoidea virens (Cooke) Takah): Susceptible Crown (black) Sheath Rot: Moderately susceptible Bacterial Panicle Blight: Moderately susceptible Straighthead: Moderately susceptible Narrow Brown Leaf Spot (Cercospora oryzae Miyake): Moderately susceptible Pest Resistance: Rice Stink Bug (Oebalus pugnax): Susceptible for discolored kernels

This invention also is directed to methods for producing a rice plant by crossing a first parent rice plant with a second parent rice plant wherein either the first or second parent rice plant is a rice plant of the line Taggart. Further, both first and second parent rice plants can come from the rice cultivar Taggart. Still further, this invention also is directed to methods for producing a rice cultivar Taggart-derived rice plant by crossing rice cultivar Taggart with a second rice plant and growing the progeny seed, and repeating the crossing and growing steps with the rice cultivar Taggart-derived plant from 0 to 7 times. Thus, any such methods using the rice cultivar Taggart are part of this invention: selfing, backcrosses, hybrid production, crosses to populations, and the like. All plants produced using rice cultivar Taggart as a parent are within the scope of this invention, including plants derived from rice cultivar Taggart. Advantageously, the rice cultivar is used in crosses with other, different, rice cultivars to produce first generation (F₁) rice seeds and plants with superior characteristics.

It should be understood that the cultivar can, through routine manipulation of cytoplasmic or other factors, be produced in a male-sterile form. Such embodiments are also contemplated within the scope of the present claims.

As used herein, the term plant includes plant cells, plant protoplasts, plant cell tissue cultures from which rice plants can be regenerated, plant calli, plant clumps, and plant cells that are intact in plants or parts of plants, such as embryos, pollen, ovules, flowers, glumes, panicles, leaves, stems, roots, root tips, anthers, pistils, and the like.

FURTHER EMBODIMENTS OF THE INVENTION

Transformation Techniques

With the advent of molecular biological techniques that have allowed the isolation and characterization of genes that encode specific protein products, scientists in the field of plant biology developed a strong interest in engineering the genome of plants to contain and express foreign genes, or additional, or modified versions of native, or endogenous, genes (perhaps driven by different promoters) in order to alter the traits of a plant in a specific manner. Such foreign additional and/or modified genes are referred to herein collectively as “transgenes.” Over the last fifteen to twenty years, several methods for producing transgenic plants have been developed, and the present invention, in particular embodiments, also relates to transformed versions of the claimed cultivar.

Culture for expressing desired structural genes and cultured cells are known in the art. Also as known in the art, rice is transformable and regenerable such that whole plants containing and expressing desired genes under regulatory control may be obtained. General descriptions of plant expression vectors and reporter genes and transformation protocols can be found in Gruber, et al., “Vectors for Plant Transformation,” in Methods in Plant Molecular Biology and Biotechnology, Glick and Thompson Eds., CRC Press, Inc., Boca Raton, pp. 89-119 (1993)). Moreover GUS expression vectors and GUS gene cassettes are available from Clone Tech Laboratories, Inc. (Palo Alto, Calif.), while luciferase expression vectors and luciferase gene cassettes are available from Pro Mega Corp. (Madison, Wis.). General methods of culturing plant tissues are provided for example by Miki, et al., “Procedures for Introducing Foreign DNA into Plants” in Methods in Plant Molecular Biology and Biotechnology, Glick and Thompson Eds., CRC Press, Inc., Boca Raton, pp. 67-88 (1993)); and by Phillips, et al., “Cell-Tissue Culture and In-Vitro Manipulation” in Corn & Corn Improvement, 3rd Edition, Sprague, et al., (Eds., pp. 345-387, American Society of Agronomy Inc. (1988)). Methods of introducing expression vectors into plant tissue include the direct infection or co-cultivation of plant cells with Agrobacterium tumefaciens, described for example by Horsch, et al., Science, 227:1229 (1985). Descriptions of Agrobacterium vector systems and methods for Agrobacterium-mediated gene transfer are provided by Gruber, et al., supra.

Useful methods include but are not limited to expression vectors introduced into plant tissues using a direct gene transfer method such as microprojectile-mediated delivery, DNA injection, electroporation, and the like. More preferably expression vectors are introduced into plant tissues using a microprojectile media delivery system with a biolistic device or using Agrobacterium-mediated transformation. Transformant plants obtained with the protoplasm of the invention are intended to be within the scope of this invention.

Plant transformation involves the construction of an expression vector which will function in plant cells. Such a vector comprises DNA comprising a gene under control of or operatively linked to a regulatory element (for example, a promoter). The expression vector may contain one or more such operably linked gene/regulatory element combinations. The vector(s) may be in the form of a plasmid, and can be used alone or in combination with other plasmids, to provide transformed rice plants, using transformation methods as described below to incorporate transgenes into the genetic material of the rice plant(s).

Expression Vectors for Transformation: Marker Genes

Expression vectors include at least one genetic marker, operably linked to a regulatory element (a promoter, for example) that allows transformed cells containing the marker to be either recovered by negative selection, i.e., inhibiting growth of cells that do not contain the selectable marker gene, or by positive selection, i.e., screening for the product encoded by the genetic marker. Many commonly used selectable marker genes for plant transformation are well known in the transformation arts, and include, for example, genes that code for enzymes that metabolically detoxify a selective chemical agent which may be an antibiotic or an herbicide, or genes that encode an altered target which is insensitive to the inhibitor. A few positive selection methods are also known in the art.

One commonly used selectable marker gene for plant transformation is the neomycin phosphotransferase II (nptII) gene, isolated from transposon Tn5, which when placed under the control of plant regulatory signals confers resistance to kanamycin. Fraley, et al., Proc. Natl. Acad. Sci. U.S.A., 80:4803 (1983). Another commonly used selectable marker gene is the hygromycin phosphotransferase gene which confers resistance to the antibiotic hygromycin. Vanden Elzen, et al., Plant Mol. Biol., 5:299 (1985).

Additional selectable marker genes of bacterial origin that confer resistance to antibiotics include gentamycin acetyl transferase, streptomycin phosphotransferase, and aminoglycoside-3′-adenyl transferase, the bleomycin resistance determinant. Hayford, et al., Plant Physiol., 86:1216 (1988); Jones, et al., Mol. Gen. Genet., 210:86 (1987); Svab, et al., Plant Mol. Biol., 14:197 (1990); Hille, et al., Plant Mol. Biol., 7:171 (1986). Other selectable marker genes confer resistance to herbicides such as glyphosate, glufosinate, or bromoxynil. Comai, et al., Nature, 317:741-744 (1985); Gordon-Kamm, et al., Plant Cell, 2:603-618 (1990), and Stalker, et al., Science, 242:419-423 (1988).

Selectable marker genes for plant transformation not of bacterial origin include, for example, mouse dihydrofolate reductase, plant 5-enolpyruvylshikimate-3-phosphate synthase, and plant acetolactate synthase. Eichholtz, et al., Somatic Cell Mol. Genet., 13:67 (1987); Shah, et al., Science, 233:478 (1986); Charest, et al., Plant Cell Rep., 8:643 (1990).

Another class of marker genes for plant transformation requires screening of presumptively transformed plant cells rather than direct genetic selection of transformed cells for resistance to a toxic substance such as an antibiotic. These genes are particularly useful to quantify or visualize the spatial pattern of expression of a gene in specific tissues and are frequently referred to as reporter genes because they can be fused to a gene or gene regulatory sequence for the investigation of gene expression. Commonly used genes for screening presumptively transformed cells include β-glucuronidase (GUS, β-galactosidase, luciferase and chloramphenicol acetyltransferase. Jefferson, R. A., Plant Mol. Biol. Rep., 5:387 (1987); Teeri, et al., EMBO J., 8:343 (1989); Koncz, et al., Proc. Natl. Acad. Sci. U.S.A., 84:131 (1987); DeBlock, et al., EMBO J., 3:1681 (1984). Another approach to the identification of relatively rare transformation events has been use of a gene that encodes a dominant constitutive regulator of the Zea mays anthocyanin pigmentation pathway. Ludwig, et al., Science, 247:449 (1990).

In vivo methods for visualizing GUS activity that do not require destruction of plant tissue are available. Molecular Probes Publication 2908, IMAGENE GREEN, pp. 1-4 (1993) and Naleway, et al., J. Cell Biol., 115:151a (1991). However, these in vivo methods for visualizing GUS activity have not proven useful for recovery of transformed cells because of low sensitivity, high fluorescent backgrounds and limitations associated with the use of luciferase genes as selectable markers.

More recently, a gene encoding Green Fluorescent Protein (GFP) has been utilized as a marker for gene expression in prokaryotic and eukaryotic cells. Chalfie, et al., Science, 263:802 (1994). GFP and mutants of GFP may be used as screenable markers.

Expression Vectors for Transformation: Promoters

Genes included in expression vectors must be driven by nucleotide sequence comprising a regulatory element, for example, a promoter. Several types of promoters are now well known in the transformation arts, as are other regulatory elements that can be used alone or in combination with promoters.

As used herein, “promoter” includes reference to a region of DNA upstream from the start of transcription and involved in recognition and binding of RNA polymerase and other proteins to initiate transcription. A “plant promoter” is a promoter capable of initiating transcription in plant cells. Examples of promoters under developmental control include promoters that preferentially initiate transcription in certain tissues, such as leaves, roots, seeds, fibers, xylem vessels, tracheids, or sclerenchyma. Such promoters are referred to as “tissue-preferred.” Promoters which initiate transcription only in certain tissue are referred to as “tissue-specific.” A “cell type” specific promoter primarily drives expression in certain cell types in one or more organs, for example, vascular cells in roots or leaves. An “inducible” promoter is a promoter which is under environmental control. Examples of environmental conditions that may effect transcription by inducible promoters include anaerobic conditions or the presence of light. Tissue-specific, tissue-preferred, cell type specific, and inducible promoters constitute the class of “non-constitutive” promoters. A “constitutive” promoter is a promoter which is active under most environmental conditions.

A. Inducible Promoters—An inducible promoter is operably linked to a gene for expression in rice. Optionally, the inducible promoter is operably linked to a nucleotide sequence encoding a signal sequence which is operably linked to a gene for expression in rice. With an inducible promoter the rate of transcription increases in response to an inducing agent.

Any inducible promoter can be used in the instant invention. See, Ward, et al., Plant Mol. Biol., 22:361-366 (1993). Exemplary inducible promoters include, but are not limited to, that from the ACEI system which responds to copper (Meft, et al., PNAS, 90:4567-4571 (1993)); in2 gene from maize which responds to benzenesulfonamide herbicide safeners (Hershey, et al., Mol. Gen. Genetics, 227:229-237 (1991) and Gatz, et al., Mol. Gen. Genetics, 243:32-38 (1994)) or Tet repressor from Tn10 (Gatz, et al., Mol. Gen. Genetics, 227:229-237 (1991)). A particularly preferred inducible promoter is a promoter that responds to an inducing agent to which plants do not normally respond. An exemplary inducible promoter is the inducible promoter from a steroid hormone gene, the transcriptional activity of which is induced by a glucocorticosteroid hormone (Schena, et al., Proc. Natl. Acad. Sci. U.S.A., 88:0421 (1991)).

B. Constitutive Promoters—A constitutive promoter is operably linked to a gene for expression in rice or the constitutive promoter is operably linked to a nucleotide sequence encoding a signal sequence which is operably linked to a gene for expression in rice.

Many different constitutive promoters can be utilized in the instant invention. Exemplary constitutive promoters include, but are not limited to, the promoters from plant viruses such as the 35S promoter from CaMV (Odell, et al., Nature, 313:810-812 (1985)) and the promoters from such genes as rice actin (McElroy, et al., Plant Cell, 2:163-171 (1990)); ubiquitin (Christensen, et al., Plant Mol. Biol., 12:619-632 (1989) and Christensen, et al., Plant Mol. Biol, 18:675-689 (1992)); pEMU (Last, et al., Theor. Appl. Genet., 81:581-588 (1991)); MAS (Velten, et al., EMBO J., 3:2723-2730 (1984)); and maize H3 histone (Lepetit, et al., Mol. Gen. Genetics, 231:276-285 (1992) and Atanassova, et al., Plant Journal 2 (3): 291-300 (1992)).

The ALS promoter, Xba1/NcoI fragment 5′ to the Brassica napus ALS3 structural gene (or a nucleotide sequence similarity to said Xba1/NcoI fragment), represents a particularly useful constitutive promoter. See, PCT Appl. No. WO 96/30530.

C. Tissue-specific or Tissue-preferred Promoters—A tissue-specific promoter is operably linked to a gene for expression in rice. Optionally, the tissue-specific promoter is operably linked to a nucleotide sequence encoding a signal sequence which is operably linked to a gene for expression in rice. Plants transformed with a gene of interest operably linked to a tissue-specific promoter produce the protein product of the transgene exclusively, or preferentially, in a specific tissue.

Any tissue-specific or tissue-preferred promoter can be utilized in the instant invention. Exemplary tissue-specific or tissue-preferred promoters include, but are not limited to, a root-preferred promoter, such as that from the phaseolin gene (Murai, et al., Science, 23:476-482 (1983) and Sengupta-Gopalan, et al., Proc. Natl. Acad. Sci. U.S.A., 82:3320-3324 (1985)); a leaf-specific and light-induced promoter such as that from cab or rubisco (Simpson, et al., EMBO J., 4(11):2723-2729 (1985) and Timko, et al., Nature, 318:579-582 (1985)); an anther-specific promoter such as that from LAT52 (Twell, et al., Mol. Gen. Genetics, 217:240-245 (1989)); a pollen-specific promoter such as that from Zm13 (Guerrero, et al., Mol. Gen. Genetics, 244:161-168 (1993)) or a microspore-preferred promoter such as that from apg (Twell, et al., Sex. Plant Reprod., 6:217-224 (1993)).

Signal Sequences for Targeting Proteins to Subcellular Compartments

Transport of protein produced by transgenes to a subcellular compartment such as the chloroplast, vacuole, peroxisome, glyoxysome, cell wall, or mitochondrion, or for secretion into the apoplast, is accomplished by means of operably linking the nucleotide sequence encoding a signal sequence to the 5′ and/or 3′ region of a gene encoding the protein of interest. Targeting sequences at the 5′ and/or 3′ end of the structural gene may determine, during protein synthesis and processing, where the encoded protein is ultimately compartmentalized.

The presence of a signal sequence directs a polypeptide to either an intracellular organelle or subcellular compartment or for secretion to the apoplast. Many signal sequences are known in the art. See, for example, Becker, et al., Plant Mol. Biol., 20:49 (1992); Close, P. S., Master's Thesis, Iowa State University (1993); Knox, C., et al., Plant Mol. Biol., 9:3-17 (1987); Lerner, et al., Plant Physiol., 91:124-129 (1989); Fontes, et al., Plant Cell, 3:483-496 (1991); Matsuoka, et al., Proc. Natl. Acad. Sci., 88:834 (1991); Gould, et al., J. Cell. Biol., 108:1657 (1989); Creissen, et al., Plant J., 2:129 (1991); Kalderon, et al., Cell, 39:499-509 (1984); Steifel, et al., Plant Cell, 2:785-793 (1990).

Foreign Protein Genes and Agronomic Genes

With transgenic plants according to the present invention, a foreign protein can be produced in commercial quantities. Thus, techniques for the selection and propagation of transformed plants, which are well understood in the art, yield a plurality of transgenic plants which are harvested in a conventional manner, and a foreign protein then can be extracted from a tissue of interest or from total biomass. Protein extraction from plant biomass can be accomplished by known methods which are discussed, for example, by Heney and Orr, Anal. Biochem., 114:92-6 (1981).

According to a preferred embodiment, the transgenic plant provided for commercial production of foreign protein is rice. In another preferred embodiment, the biomass of interest is seed. For the relatively small number of transgenic plants that show higher levels of expression, a genetic map can be generated, primarily via conventional RFLP, PCR, and SSR analysis, which identifies the approximate chromosomal location of the integrated DNA molecule. For exemplary methodologies in this regard, see Methods in Plant Molecular Biology and Biotechnology, Glick and Thompson Eds., CRC Press, Inc., Boca Raton, pp. 269-284 (1993)). Map information concerning chromosomal location is useful for proprietary protection of a subject transgenic plant. If unauthorized propagation is undertaken and crosses made with other germplasm, the map of the integration region can be compared to similar maps for suspect plants, to determine if the latter have a common parentage with the subject plant. Map comparisons would involve hybridizations, RFLP, PCR, SSR, and sequencing, all of which are conventional techniques.

Through the transformation of rice, the expression of genes can be altered to enhance disease resistance, insect resistance, herbicide resistance, agronomic quality and other traits. Transformation can also be used to insert DNA sequences which control or help control male-sterility. DNA sequences native to rice as well as non-native DNA sequences can be transformed into rice and used to alter levels of native or non-native proteins. Various promoters, targeting sequences, enhancing sequences, and other DNA sequences can be inserted into the genome for the purpose of altering the expression of proteins. Reduction of the activity of specific genes (also known as gene silencing, or gene suppression) is desirable for several aspects of genetic engineering in plants.

Many techniques for gene silencing are well-known to one of skill in the art, including, but not limited to, knock-outs (such as by insertion of a transposable element such as mu (Vicki Chandler, The Maize Handbook, ch. 118, Springer-Verlag (1994)) or other genetic elements such as a FRT, Lox, or other site specific integration site, antisense technology (see, e.g., Sheehy, et al., PNAS USA, 85:8805-8809 (1988); and U.S. Pat. Nos. 5,107,065; 5,453,566; and 5,759,829); co-suppression (e.g., Taylor, Plant Cell, 9:1245 (1997); Jorgensen, Trends Biotech., 8(12):340-344 (1990); Flavell, PNAS USA, 91:3490-3496 (1994); Finnegan, et al., Bio/Technology, 12: 883-888 (1994); and Neuhuber, et al., Mol. Gen. Genet., 244:230-241 (1994)); RNA interference (Napoli, et al., Plant Cell, 2:279-289 (1990); U.S. Pat. No. 5,034,323; Sharp, Genes Dev., 13:139-141 (1999); Zamore, et al., Cell, 101:25-33 (2000); and Montgomery, et al., PNAS USA, 95:15502-15507 (1998)); virus-induced gene silencing (Burton, et al., Plant Cell, 12:691-705 (2000); and Baulcombe, Curr. Op. Plant Bio., 2:109-113 (1999)); target-RNA-specific ribozymes (Haseloff, et al., Nature, 334: 585-591 (1988)); hairpin structures (Smith, et al., Nature, 407:319-320 (2000); WO 99/53050; and WO 98/53083); MicroRNA (Aukerman & Sakai, Plant Cell, 15:2730-2741 (2003)); ribozymes (Steinecke, et al., EMBO J., 11:1525 (1992); and Perriman, et al., Antisense Res. Dev., 3:253 (1993)); oligonucleotide mediated targeted modification (e.g., PCT Publication Nos. WO 03/076574 and WO 99/25853); Zn-finger targeted molecules (e.g., PCT Publication Nos. WO 01/52620; WO 03/048345; and WO 00/42219); and other methods or combinations of the above methods known to those of skill in the art.

Likewise, by means of the present invention, agronomic genes can be expressed in transformed plants. More particularly, plants can be genetically engineered to express various phenotypes of agronomic interest. Exemplary genes implicated in this regard include, but are not limited to, those categorized below:

1. Genes that Confer Resistance to Pests or Disease and that Encode:

A. Plant disease resistance genes. Plant defenses are often activated by specific interaction between the product of a disease resistance gene (R) in the plant and the product of a corresponding avirulence (Avr) gene in the pathogen. A plant cultivar can be transformed with cloned resistance gene to engineer plants that are resistant to specific pathogen strains. See, for example, Jones, et al., Science, 266:789 (1994) (cloning of the tomato Cf-9 gene for resistance to Cladosporium fulvum); Martin, et al., Science, 262:1432 (1993) (tomato Pto gene for resistance to Pseudomonas syringae pv. tomato encodes a protein kinase); Mindrinos, et al., Cell, 78:1089 (1994) (Arabidopsis RSP2 gene for resistance to Pseudomonas syringae); McDowell & Woffenden, Trends Biotechnol., 21(4):178-83 (2003); and Toyoda, et al., Transgenic Res., 11 (6):567-82 (2002).

B. A Bacillus thuringiensis protein, a derivative thereof or a synthetic polypeptide modeled thereon. See, for example, Geiser, et al., Gene, 48:109 (1986), who disclose the cloning and nucleotide sequence of a Bt δ-endotoxin gene. Moreover, DNA molecules encoding δ-endotoxin genes can be purchased from American Type Culture Collection, Manassas, Va., for example, under ATCC Accession Nos. 40098, 67136, 31995, and 31998.

C. A lectin. See, for example, the disclosure by Van Damme, et al., Plant Molec. Biol., 24:25 (1994), who disclose the nucleotide sequences of several Clivia miniata mannose-binding lectin genes.

D. A vitamin-binding protein such as avidin. See, PCT Appl. No. US 93/06487. The application teaches the use of avidin and avidin homologues as larvicides against insect pests.

E. An enzyme inhibitor, for example, a protease or proteinase inhibitor or an amylase inhibitor. See, for example, Abe, et al., J. Biol. Chem., 262:16793 (1987) (nucleotide sequence of rice cysteine proteinase inhibitor); Huub, et al., Plant Molec. Biol., 21:985 (1993) (nucleotide sequence of cDNA encoding tobacco proteinase inhibitor I); Sumitani, et al., Biosci. Biotech. Biochem., 57:1243 (1993) (nucleotide sequence of Streptomyces nitrosporeus α-amylase inhibitor).

F. An insect-specific hormone or pheromone such as an ecdysteroid and juvenile hormone, a variant thereof, a mimetic based thereon, or an antagonist or agonist thereof. See, for example, the disclosure by Hammock, et al., Nature, 344:458 (1990), of baculovirus expression of cloned juvenile hormone esterase, an inactivator of juvenile hormone.

G. An insect-specific peptide or neuropeptide which, upon expression, disrupts the physiology of the affected pest. For example, see the disclosures of Regan, J. Biol. Chem., 269:9 (1994) (expression cloning yields DNA coding for insect diuretic hormone receptor), and Pratt, et al., Biochem. Biophys. Res. Comm., 163:1243 (1989) (an allostatin is identified in Diploptera puntata). See also, U.S. Pat. No. 5,266,317 to Tomalski, et al., who disclose genes encoding insect-specific, paralytic neurotoxins.

H. An insect-specific venom produced in nature by a snake, a wasp, etc. For example, see Pang, et al., Gene, 116:165 (1992), for disclosure of heterologous expression in plants of a gene coding for a scorpion insectotoxic peptide.

I. An enzyme responsible for a hyper-accumulation of a monoterpene, a sesquiterpene, a steroid, a hydroxamic acid, a phenylpropanoid derivative or another non-protein molecule with insecticidal activity.

J. An enzyme involved in the modification, including the post-translational modification, of a biologically active molecule; for example, a glycolytic enzyme, a proteolytic enzyme, a lipolytic enzyme, a nuclease, a cyclase, a transaminase, an esterase, a hydrolase, a phosphatase, a kinase, a phosphorylase, a polymerase, an elastase, a chitinase, and a glucanase, whether natural or synthetic. See, PCT Publication No. WO 93/02197 in the name of Scott, et al., which discloses the nucleotide sequence of a callase gene. DNA molecules which contain chitinase-encoding sequences can be obtained, for example, from the ATCC under Accession Nos. 39637 and 67152. See also, Kramer, et al., Insect Biochem. Molec. Biol., 23:691 (1993), who teach the nucleotide sequence of a cDNA encoding tobacco hornworm chitinase, and Kawalleck, et al., Plant Molec. Biol., 21:673 (1993), who provide the nucleotide sequence of the parsley ubi4-2 polyubiquitin gene.

K. A molecule that stimulates signal transduction. For example, see the disclosure by Botella, et al., Plant Molec. Biol., 24:757 (1994), of nucleotide sequences for mung bean calmodulin cDNA clones, and Griess, et al., Plant Physiol., 104:1467 (1994), who provide the nucleotide sequence of a maize calmodulin cDNA clone.

L. A hydrophobic moment peptide. See, PCT Publication No. WO 95/16776 (disclosure of peptide derivatives of Tachyplesin which inhibit fungal plant pathogens) and PCT Publication No. WO 95/18855 (teaches synthetic antimicrobial peptides that confer disease resistance), the respective contents of which are hereby incorporated by reference.

M. A membrane permease, a channel former or a channel blocker. For example, see the disclosure of Jaynes, et al., Plant Sci, 89:43 (1993), of heterologous expression of a cecropin-β, lytic peptide analog to render transgenic tobacco plants resistant to Pseudomonas solanacearum.

N. A viral-invasive protein or a complex toxin derived therefrom. For example, the accumulation of viral coat proteins in transformed plant cells imparts resistance to viral infection and/or disease development effected by the virus from which the coat protein gene is derived, as well as by related viruses. See, Beachy, et al., Ann. Rev. Phytopathol., 28:451 (1990). Coat protein-mediated resistance has been conferred upon transformed plants against alfalfa mosaic virus, cucumber mosaic virus, tobacco streak virus, potato virus X, potato virus Y, tobacco etch virus, tobacco rattle virus, and tobacco mosaic virus. Id.

O. An insect-specific antibody or an immunotoxin derived therefrom. Thus, an antibody targeted to a critical metabolic function in the insect gut would inactivate an affected enzyme, killing the insect. Cf. Taylor, et al., Abstract #497, Seventh International Symposium on Molecular Plant-Microbe Interactions (Edinburgh, Scotland (1994)) (enzymatic inactivation in transgenic tobacco via production of single-chain antibody fragments).

P. A virus-specific antibody. See, for example, Tavladoraki, et al., Nature, 366:469 (1993), who show that transgenic plants expressing recombinant antibody genes are protected from virus attack.

Q. A developmental-arrestive protein produced in nature by a pathogen or a parasite. Thus, fungal endo-α-1,4-D-polygalacturonases facilitate fungal colonization and plant nutrient release by solubilizing plant cell wall homo-α-1,4-D-galacturonase. See, Lamb, et al., Bio/Technology, 10:1436 (1992). The cloning and characterization of a gene which encodes a bean endopolygalacturonase-inhibiting protein is described by Toubart, et al., Plant J., 2:367 (1992).

R. A developmental-arrestive protein produced in nature by a plant. For example, Logemann, et al., Bio/Technology, 10:305 (1992), have shown that transgenic plants expressing the barley ribosome-inactivating gene have an increased resistance to fungal disease.

S. Genes involved in the Systemic Acquired Resistance (SAR) Response and/or the pathogenesis-related genes. Briggs, S., Current Biology, 5(2) (1995); Pieterse & Van Loon, Curr. Opin. Plant Bio., 7(4):456-64 (2004) and Somssich, Cell, 113(7):815-6 (2003).

T. Antifungal genes. See, Cornelissen and Melchers, Plant Physiol., 101:709-712 (1993); Parijs, et al., Planta, 183:258-264 (1991) and Bushnell, et al., Can. J. of Plant Path., 20(2):137-149 (1998). See also, U.S. Pat. No. 6,875,907.

U. Detoxification genes, such as for fumonisin, beauvericin, moniliformin, and zearalenone, and their structurally related derivatives. For example, see U.S. Pat. No. 5,792,931.

V. Cystatin and cysteine proteinase inhibitors. See U.S. Pat. No. 7,205,453.

W. Defensin genes. See PCT Publication No. WO 03/000863 and U.S. Pat. No. 6,911,577.

2. Genes that Confer Resistance to an Herbicide, for Example:

A. An herbicide that inhibits the growing point or meristem, such as an imidazolinone or a sulfonylurea. Exemplary genes in this category code for mutant ALS and AHAS enzyme as described, for example, by Lee, et al., EMBO J., 7:1241 (1988) and Miki, et al., Theor. Appl. Genet., 80:449 (1990), respectively.

B. Glyphosate (resistance conferred by mutant 5-enolpyruvlshikimate-3-phosphate synthase (EPSP) and aroA genes, respectively) and other phosphono compounds such as glufosinate (phosphinothricin acetyl transferase (PAT) and Streptomyces hygroscopicus PAT, bar, genes), and pyridinoxy or phenoxy propionic acids and cyclohexones (ACCase inhibitor-encoding genes). See, for example, U.S. Pat. No. 4,940,835 to Shah, et al., which discloses the nucleotide sequence of a form of EPSP which can confer glyphosate resistance. A DNA molecule encoding a mutant aroA gene can be obtained under ATCC Accession No. 39256, and the nucleotide sequence of the mutant gene is disclosed in U.S. Pat. No. 4,769,061 to Comai. European Pat. Appl. No. 0 333 033 to Kumada, et al. and U.S. Pat. No. 4,975,374 to Goodman, et al., disclose nucleotide sequences of glutamine synthetase genes which confer resistance to herbicides such as L-phosphinothricin. The nucleotide sequence of a PAT gene is provided in European Pat. Appl. No. 0 242 246 to Leemans, et al. DeGreef, et al., Bio/Technology, 7:61 (1989), describe the production of transgenic plants that express chimeric bar genes coding for PAT activity. Exemplary of genes conferring resistance to phenoxy propionic acids and cyclohexones, such as sethoxydim and haloxyfop are the Acc1-S1, Acc1-S2, and Acc1-S3 genes described by Marshall, et al., Theor. Appl. Genet., 83:435 (1992).

C. An herbicide that inhibits photosynthesis, such as a triazine (psbA and gs+genes) or a benzonitrile (nitrilase gene). Przibilla, et al., Plant Cell, 3:169 (1991), describe the transformation of Chlamydomonas with plasmids encoding mutant psbA genes. Nucleotide sequences for nitrilase genes are disclosed in U.S. Pat. No. 4,810,648 to Stalker, and DNA molecules containing these genes are available under ATCC Accession Nos. 53435, 67441, and 67442. Cloning and expression of DNA coding for a glutathione S-transferase is described by Hayes, et al., Biochem. J., 285:173 (1992).

3. Genes that Confer or Contribute to a Value-Added Trait, such as:

A. Modified fatty acid metabolism, for example, by transforming a plant with an antisense gene of stearyl-ACP desaturase to increase stearic acid content of the plant. See, Knultzon, et al., Proc. Natl. Acad. Sci. U.S.A., 89:2624 (1992).

B. Decreased phytate content. 1) Introduction of a phytase-encoding gene would enhance breakdown of phytate, adding more free phosphate to the transformed plant. For example, see, Van Hartingsveldt, et al., Gene, 127:87 (1993), for a disclosure of the nucleotide sequence of an Aspergillus niger phytase gene; 2) A gene could be introduced that reduced phytate content. In maize, this, for example, could be accomplished by cloning and then reintroducing DNA associated with the single allele which is responsible for maize mutants characterized by low levels of phytic acid. See, Raboy, et al., Maydica, 35:383 (1990).

C. Modified carbohydrate composition effected, for example, by transforming plants with a gene coding for an enzyme that alters the branching pattern of starch. See, Shiroza, et al., J. Bacteol., 170:810 (1988) (nucleotide sequence of Streptococcus mutants fructosyltransferase gene); Steinmetz, et al., Mol. Gen. Genet., 20:220 (1985) (nucleotide sequence of Bacillus subtilis levansucrase gene); Pen, et al., Bio/Technology, 10:292 (1992) (production of transgenic plants that express Bacillus lichenifonnis α-amylase); Elliot, et al., Plant Molec. Biol., 21:515 (1993) (nucleotide sequences of tomato invertase genes); Søgaard, et al., J. Biol. Chem., 268:22480 (1993) (site-directed mutagenesis of barley α-amylase gene); and Fisher, et al., Plant Physiol., 102:1045 (1993) (maize endosperm starch branching enzyme 11).

4. Genes that Control Male Sterility:

There are several methods of conferring genetic male sterility available, such as multiple mutant genes at separate locations within the genome that confer male sterility, as disclosed in U.S. Pat. Nos. 4,654,465 and 4,727,219 to Brar, et al., and chromosomal translocations as described by Patterson in U.S. Pat. Nos. 3,861,709 and 3,710,511. In addition to these methods, Albertsen, et al., U.S. Pat. No. 5,432,068, describes a system of nuclear male sterility which includes: identifying a gene which is critical to male fertility; silencing this native gene which is critical to male fertility; removing the native promoter from the essential male fertility gene and replacing it with an inducible promoter; inserting this genetically engineered gene back into the plant; and thus creating a plant that is male sterile because the inducible promoter is not “on” resulting in the male fertility gene not being transcribed. Fertility is restored by inducing, or turning “on,” the promoter, which in turn allows the gene that confers male fertility to be transcribed.

A. A tapetum-specific gene, RTS, a rice anther-specific gene is required for male fertility and its promoter sequence directs tissue-specific gene expression in different plant species. Luo, Hong, et. al., Plant Molecular Biology., 62(3): 397-408(12) (2006). Introduction of a deacetylase gene under the control of a tapetum-specific promoter and with the application of the chemical N-Ac-PPT. See International Publication No. WO 01/29237.

B. Introduction of various stamen-specific promoters. Rice anther-specific promoters which are of particular utility in the production of transgenic male-sterile monocots and plants for restoring their fertility. See, U.S. Pat. No. 5,639,948. See also, International Publication Nos. WO 92/13956 and WO 92/13957.

C. Introduction of the barnase and the barstar genes. See, Paul, et al., Plant Mol. Biol., 19:611-622 (1992).

For additional examples of nuclear male and female sterility systems and genes, see also, U.S. Pat. Nos. 5,859,341, 6,297,426, 5,478,369, 5,824,524, 5,850,014, and 6,265,640. See also, Hanson, Maureen R., et. al., “Interactions of Mitochondrial and Nuclear Genes That Affect Male Gametophyte Development,” Plant Cell., 16:S154-S169 (2004), all of which are hereby incorporated by reference.

5. Genes that Create a Site for Site Specific DNA Integration:

This includes the introduction of FRT sites that may be used in the FLP/FRT system and/or Lox sites that may be used in the Cre/Loxp system. For example, see, Lyznik, et al., Site-Specific Recombination for Genetic Engineering in Plants, Plant Cell Rep, 21:925-932 (2003) and International Publication No. WO 99/25821, which are hereby incorporated by reference. Other systems that may be used include the Gin recombinase of phage Mu (Maeser, et al. (1991); Vicki Chandler, The Maize Handbook, ch. 118, Springer-Verlag (1994), the Pin recombinase of E. coli (Enomoto, et al. (1983)), and the R/RS system of the pSRi plasmid (Araki, et al. (1992)).

6. Genes that Affect Abiotic Stress Resistance:

Genes that affect abiotic stress resistance (including, but not limited to, flowering, panicle/glume and seed development, enhancement of nitrogen utilization efficiency, altered nitrogen responsiveness, drought resistance or tolerance, cold resistance or tolerance, and salt resistance or tolerance) and increased yield under stress. For example, see: Xiong, Lizhong, et al., “Disease Resistance and Abiotic Stress Tolerance in Rice Are Inversely Modulated by an Abscisic Acid-inducible Mitogen-Activated Protein Kinase,” The Plant Cell., 15:745-759 (2003), where OsMAPK5 can positively regulate drought, salt, and cold tolerance and negatively modulate PRgene expression and broad-spectrum disease resistance in rice; Chen, Fang, et. al., “The Rice 14-3-3 Gene Family and its Involvement in Responses to Biotic and Abiotic Stress,” DNA Research, 13(2):53-63 (2006), where at least four rice GF14 genes, GF14b, GF14c, GF14e, and Gf14f, were differentially regulated by salinity, drought, wounding, and abscisic acid; International Publication No. WO 00/73475 where water use efficiency is altered through alteration of malate; U.S. Pat. Nos. 5,892,009, 5,965,705, 5,929,305, 5,891,859, 6,417,428, 6,664,446, 6,717,034, and 6,801,104, and International Publication Nos. WO 2000/060089, WO 2001/026459, WO 2001/035725, WO 2001/034726, WO 2001/035727, WO 2001/036444, WO 2001/036597, WO 2001/036598, WO 2002/015675, WO 2002/017430, WO 2002/077185, WO 2002/079403, WO 2003/013227, WO 2003/013228, WO 2003/014327, WO 2004/031349, WO 2004/076638, WO 98/09521, and WO 99/38977 describing genes, including CBF genes and transcription factors effective in mitigating the negative effects of freezing, high salinity, and drought on plants, as well as conferring other positive effects on plant phenotype; U.S. Publication No. 2004/0148654 and International Publication No. WO 01/36596 where abscisic acid is altered in plants resulting in improved plant phenotype such as increased yield and/or increased tolerance to abiotic stress; International Publication Nos. WO 2000/006341 and WO 04/090143, U.S. Publication No. 2004/0237147, and U.S. Pat. No. 6,992,237, where cytokinin expression is modified resulting in plants with increased stress tolerance, such as drought tolerance and/or increased yield. Also see, International Publication Nos. WO 02/02776, WO 2003/052063, WO 01/64898, JP 2002281975, and U.S. Pat. Nos. 6,084,153, 6,177,275, and 6,107,547 (enhancement of nitrogen utilization and altered nitrogen responsiveness). For ethylene alteration, see, U.S. Publication Nos. 2004/0128719 and 2003/0166197 and International Publication No. WO 2000/32761. For plant transcription factors or transcriptional regulators of abiotic stress, see, e.g., U.S. Publication Nos. 2004/0098764 and 2004/0078852.

Other genes and transcription factors that affect plant growth and agronomic traits such as yield, flowering, plant growth, and/or plant structure, can be introduced or introgressed into plants, see, e.g., International Publication Nos. WO 97/49811 (LHY), WO 98/56918 (ESD4), WO 97/10339, WO 96/14414 (CON), WO 96/38560, WO 01/21822 (VRN1), WO 00/44918 (VRN2), WO 99/49064 (GI), WO 00/46358 (FR1), WO 97/29123, WO 99/09174 (D8 and Rht), and U.S. Pat. Nos. 6,573,430 (TFL), 6,713,663 (FT), 6,794,560, 6,307,126 (GAI), and International Publication Nos. WO 2004/076638 and WO 2004/031349 (transcription factors).

Methods for Rice Transformation

Numerous methods for plant transformation have been developed, including biological and physical plant transformation protocols. See, for example, Miki, et al., “Procedures for Introducing Foreign DNA into Plants,” in Methods in Plant Molecular Biology and Biotechnology, Glick and Thompson Eds., CRC Press, Inc., Boca Raton, pp. 67-88 (1993)). In addition, expression vectors and in vitro culture methods for plant cell or tissue transformation and regeneration of plants are available. See, for example, Gruber, et al., “Vectors for Plant Transformation,” in Methods in Plant Molecular Biology and Biotechnology, Glick and Thompson Eds., CRC Press, Inc., Boca Raton, pp. 89-119 (1993).

A. Agrobacterium-mediated Transformation—One method for introducing an expression vector into plants is based on the natural transformation system of Agrobacterium. See, for example, Horsch, et al., Science, 227:1229 (1985). A. tumefaciens and A. rhizogenes are plant pathogenic soil bacteria which genetically transform plant cells. The Ti and Ri plasmids of A. tumefaciens and A. rhizogenes, respectively, carry genes responsible for genetic transformation of the plant. See, for example, Kado, C. I., Crit. Rev. Plant Sci., 10:1 (1991). Descriptions of Agrobacterium vector systems and methods for Agrobacterium-mediated gene transfer are provided by Gruber, et al., supra, Miki, et al., supra, and Moloney, et al., Plant Cell Reports, 8:238 (1989). See also, U.S. Pat. No. 5,591,616, issued Jan. 7, 1997.

B. Direct Gene Transfer—Despite the fact the host range for Agrobacterium-mediated transformation is broad, some major cereal crop species and gymnosperms have generally been recalcitrant to this mode of gene transfer, even though some success has recently been achieved in rice and corn. Hiei, et al., The Plant Journal, 6:271-282 (1994) and U.S. Pat. No. 5,591,616, issued Jan. 7, 1997. Several methods of plant transformation, collectively referred to as direct gene transfer, have been developed as an alternative to Agrobacterium-mediated transformation.

A generally applicable method of plant transformation is microprojectile-mediated transformation wherein DNA is carried on the surface of microprojectiles measuring 1 to 4 μm. The expression vector is introduced into plant tissues with a biolistic device that accelerates the microprojectiles to speeds of 300 to 600 m/s which is sufficient to penetrate plant cell walls and membranes. Sanford, et al., Part. Sci. Technol., 5:27 (1987); Sanford, J. C., Trends Biotech., 6:299 (1988); Klein, et al., Bio/Technology, 6:559-563 (1988); Sanford, J. C., Physiol Plant, 7:206 (1990); Klein, et al., Biotechnology, 10:268 (1992). In corn, several target tissues can be bombarded with DNA-coated microprojectiles in order to produce transgenic plants, including, for example, callus (Type I or Type II), immature embryos, and meristematic tissue.

Another method for physical delivery of DNA to plants is sonication of target cells. Zhang, et al., Bio/Technology, 9:996 (1991). Additionally, liposome and spheroplast fusion have been used to introduce expression vectors into plants. Deshayes, et al., EMBO J, 4:2731 (1985); Christou, et al., Proc Natl. Acad. Sci. U.S.A., 84:3962 (1987). Direct uptake of DNA into protoplasts using CaCl₂ precipitation, polyvinyl alcohol or poly-L-ornithine has also been reported. Hain, et al., Mol. Gen. Genet., 199:161 (1985) and Draper, et al., Plant Cell Physiol., 23:451 (1982). Electroporation of protoplasts and whole cells and tissues have also been described. Donn, et al., In Abstracts of VIIth International Congress on Plant Cell and Tissue Culture IAPTC, A2-38, p. 53 (1990); D'Halluin, et al., Plant Cell, 4:1495-1505 (1992); and Spencer, et al., Plant Mol. Biol., 24:51-61 (1994).

Following transformation of rice target tissues, expression of the above-described selectable marker genes allows for preferential selection of transformed cells, tissues, and/or plants using regeneration and selection methods now well known in the art.

Genetic Marker Profile Through SSR and First Generation Progeny

In addition to phenotypic observations, a plant can also be identified by its genotype. The genotype of a plant can be characterized through a genetic marker profile which can identify plants of the same variety or a related variety or be used to determine or validate a pedigree. Genetic marker profiles can be obtained by techniques such as Isozyme Electrophoresis, Restriction Fragment Length Polymorphisms (RFLPs), Randomly Amplified Polymorphic DNAs (RAPDs), Arbitrarily Primed Polymerase Chain Reaction (AP-PCR), DNA Amplification Fingerprinting (DAF), Sequence Characterized Amplified Regions (SCARs), Amplified Fragment Length Polymorphisms (AFLPs), Simple Sequence Repeats (SSRs), which are also referred to as Microsatellites, and Single Nucleotide Polymorphisms (SNPs). For example, see, Cregan et. al, “An Integrated Genetic Linkage Map of the Soybean Genome,” Crop Science, 39:1464-1490 (1999), and Berry, et al., Assessing Probability of Ancestry Using Simple Sequence Repeat Profiles: Applications to Maize Inbred Lines and Soybean Varieties,” Genetics, 165:331-342 (2003), each of which are incorporated by reference herein in their entirety.

Particular markers used for these purposes are not limited to any particular set of markers, but are envisioned to include any type of marker and marker profile which provides a means of distinguishing varieties. One method of comparison is to use only homozygous loci for rice cultivar Taggart.

Primers and PCR protocols for assaying these and other markers are widely known in the art. In addition to being used for identification of rice cultivar Taggart and plant parts and plant cells of rice cultivar Taggart, the genetic profile may be used to identify a rice plant produced through the use of rice cultivar Taggart or to verify a pedigree for progeny plants produced through the use of rice cultivar Taggart. The genetic marker profile is also useful in breeding and developing backcross conversions.

The present invention comprises a rice hybrid plant characterized by molecular and physiological data obtained from the representative sample of said hybrid deposited with the American Type Culture Collection (ATCC). Further provided by the invention is a rice hybrid plant formed by the combination of the disclosed rice hybrid plant or plant cell with another rice plant or cell.

Means of performing genetic marker profiles using SSR polymorphisms are well known in the art. SSRs are genetic markers based on polymorphisms in repeated nucleotide sequences, such as microsatellites. A marker system based on SSRs can be highly informative in linkage analysis relative to other marker systems in that multiple alleles may be present. Another advantage of this type of marker is that, through use of flanking primers, detection of SSRs can be achieved, for example, by the polymerase chain reaction (PCR), thereby eliminating the need for labor-intensive Southern hybridization. The PCR detection is done by use of two oligonucleotide primers flanking the polymorphic segment of repetitive DNA. Repeated cycles of heat denaturation of the DNA followed by annealing of the primers to their complementary sequences at low temperatures, and extension of the annealed primers with DNA polymerase, comprise the major part of the methodology.

Following amplification, markers can be scored by electrophoresis of the amplification products. Scoring of marker genotype is based on the size of the amplified fragment, which may be measured by the number of base pairs of the fragment. While variation in the primer used or in laboratory procedures can affect the reported fragment size, relative values should remain constant regardless of the specific primer or laboratory used. When comparing hybrids or varieties it is preferable if all SSR profiles are performed in the same lab.

Primers used are publicly available and may be found in for example in U.S. Pat. Nos. 7,232,940, 7,217,003, 7,250,556, 7,214,851, 7,195,887, and 7,192,774.

In addition, plants and plant parts substantially benefiting from the use of rice cultivar Taggart in their development, such as rice cultivar Taggart comprising a backcross conversion, transgene, or genetic sterility factor, may be identified by having a molecular marker profile with a high percent identity to rice cultivar Taggart. Such a percent identity might be 95%, 96%, 97%, 98%, 99%, 99.5%, or 99.9% identical to rice cultivar Taggart.

The SSR profile of rice cultivar Taggart also can be used to identify essentially derived varieties and other progeny varieties developed from the use of rice cultivar Taggart, as well as cells and other plant parts thereof. Such plants may be developed using the markers identified in International Publication No. WO 00/31964, U.S. Pat. No. 6,162,967, and U.S. application Ser. No. 09/954,773. Progeny plants and plant parts produced using rice cultivar Taggart may be identified by having a molecular marker profile of at least 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 99.5% genetic contribution from a rice hybrid or variety, as measured by either percent identity or percent similarity. Such progeny may be further characterized as being within a pedigree distance of rice cultivar Taggart, such as within 1, 2, 3, 4, or 5 or fewer cross-pollinations to a rice plant other than rice cultivar Taggart or a plant that has rice cultivar Taggart as a progenitor. Unique molecular profiles may be identified with other molecular tools such as SNPs and RFLPs.

While determining the SSR genetic marker profile of the plants described supra, several unique SSR profiles may also be identified which did not appear in either parent of such rice plant. Such unique SSR profiles may arise during the breeding process from recombination or mutation. A combination of several unique alleles provides a means of identifying a plant variety, an F₁ progeny produced from such variety, and progeny produced from such rice plan.

The foregoing methods for transformation would typically be used for producing a transgenic cultivar. The transgenic cultivar could then be crossed, with another (non-transformed or transformed) cultivar, in order to produce a new transgenic cultivar. Alternatively, a genetic trait which has been engineered into a particular rice cultivar using the foregoing transformation techniques could be moved into another cultivar using traditional backcrossing techniques that are well known in the plant breeding arts. For example, a backcrossing approach could be used to move an engineered trait from a public, non-elite cultivar into an elite cultivar, or from a cultivar containing a foreign gene in its genome into a cultivar which does not contain that gene. As used herein, “crossing” can refer to a simple X by Y cross, or the process of backcrossing, depending on the context.

Gene Conversion

When the term “rice plant” is used in the context of the present invention, this also includes any gene conversions of that cultivar. The term gene converted plant as used herein refers to those rice plants which are developed by a plant breeding technique called backcrossing wherein essentially all of the desired morphological and physiological characteristics of a cultivar are recovered in addition to the one or more genes transferred into the cultivar via the backcrossing technique. Backcrossing methods can be used with the present invention to improve or introduce a characteristic into the cultivar. The term backcrossing as used herein refers to the repeated crossing of a hybrid progeny back to one of the parental rice plants, the recurrent parent, for that cultivar, i.e., backcrossing 1, 2, 3, 4, 5, 6, 7, 8, 9, or more times to the recurrent parent. The parental rice plant which contributes the gene for the desired characteristic is termed the nonrecurrent or donor parent. This terminology refers to the fact that the nonrecurrent parent is used one time in the backcross protocol and therefore does not recur. The parental rice plant to which the gene or genes from the nonrecurrent parent are transferred is known as the recurrent parent as it is used for several rounds in the backcrossing protocol (Poehlman & Sleper (1994); Fehr (1987)). In a typical backcross protocol, the original cultivar of interest (recurrent parent) is crossed to a second cultivar (nonrecurrent parent) that carries the single gene or genes of interest to be transferred. The resulting progeny from this cross are then crossed again to the recurrent parent and the process is repeated until a rice plant is obtained wherein essentially all of the desired morphological and physiological characteristics of the recurrent parent are recovered in the converted plant, in addition to one or more transferred genes from the nonrecurrent parent as determined at the 5% significance level when grown in the same environmental conditions.

The selection of a suitable recurrent parent is an important step for a successful backcrossing procedure. The goal of a backcross protocol is to alter or substitute one or more traits or characteristics in the original cultivar. To accomplish this, one or more genes of the recurrent cultivar is modified or substituted with the desired gene or genes from the nonrecurrent parent, while retaining essentially all of the rest of the desired genetic, and therefore the desired physiological and morphological, constitution of the original cultivar. The choice of the particular nonrecurrent parent will depend on the purpose of the backcross; one of the major purposes is to add some commercially desirable, agronomically important trait to the plant. The exact backcrossing protocol will depend on the characteristic or trait being altered to determine an appropriate testing protocol. Although backcrossing methods are simplified when the characteristic(s) being transferred is a dominant allele, a recessive allele may also be transferred. In this instance it may be necessary to introduce a test of the progeny to determine if the desired characteristic has been successfully transferred.

Many single gene traits have been identified that are not regularly selected for in the development of a new cultivar but that can be improved by backcrossing techniques. Single gene traits may or may not be transgenic. Examples of these traits include, but are not limited to, male sterility, waxy starch, herbicide resistance, resistance for bacterial, fungal, or viral disease, insect resistance, male fertility, enhanced nutritional quality, industrial usage, yield stability, and yield enhancement. These genes are generally inherited through the nucleus. Some known exceptions to this are the genes for male sterility, some of which are inherited cytoplasmically, but still act as single gene traits. Several of these single gene traits are described in U.S. Pat. Nos. 5,777,196, 5,948,957, and 5,969,212, the disclosures of which are specifically hereby incorporated by reference.

Introduction of a New Trait or Locus into Rice Cultivar Taggart

Rice cultivar Taggart represents a new base genetic hybrid into which a new locus or trait may be introgressed. Direct transformation and backcrossing represent two important methods that can be used to accomplish such an introgression. The term backcross conversion and single locus conversion are used interchangeably to designate the product of a backcrossing program.

Backcross Conversions of Rice Cultivar Taggart

A backcross conversion of rice cultivar Taggart occurs when DNA sequences are introduced through backcrossing (Hallauer, et al., “Corn Breeding,” Corn and Corn Improvements, No. 18, pp. 463-481 (1988)), with rice cultivar Taggart utilized as the recurrent parent. Both naturally occurring and transgenic DNA sequences may be introduced through backcrossing techniques. A backcross conversion may produce a plant with a trait or locus conversion in at least two or more backcrosses, including at least 2 crosses, at least 3 crosses, at least 4 crosses, at least 5 crosses, and the like. Molecular marker assisted breeding or selection may be utilized to reduce the number of backcrosses necessary to achieve the backcross conversion. For example, see, Openshaw, S. J., et al., Marker-assisted Selection in Backcross Breeding, in: Proceedings Symposium of the Analysis of Molecular Data, Crop Science Society of America, Corvallis, Oreg. (August 1994), where it is demonstrated that a backcross conversion can be made in as few as two backcrosses.

The complexity of the backcross conversion method depends on the type of trait being transferred (single genes or closely linked genes as vs. unlinked genes), the level of expression of the trait, the type of inheritance (cytoplasmic or nuclear) and the types of parents included in the cross. It is understood by those of ordinary skill in the art that for single gene traits that are relatively easy to classify, the backcross method is effective and relatively easy to manage. (See, Hallauer, et al., in Corn and Corn Improvement, Sprague and Dudley, Third Ed. (1998)). Desired traits that may be transferred through backcross conversion include, but are not limited to, sterility (nuclear and cytoplasmic), fertility restoration, nutritional enhancements, drought tolerance, nitrogen utilization, altered fatty acid profile, low phytate, industrial enhancements, disease resistance (bacterial, fungal or viral), insect resistance, and herbicide resistance. In addition, an introgression site itself, such as an FRT site, Lox site, or other site specific integration site, may be inserted by backcrossing and utilized for direct insertion of one or more genes of interest into a specific plant variety. In some embodiments of the invention, the number of loci that may be backcrossed into rice cultivar Taggart is at least 1, 2, 3, 4, or 5, and/or no more than 6, 5, 4, 3, or 2. A single locus may contain several transgenes, such as a transgene for disease resistance that, in the same expression vector, also contains a transgene for herbicide resistance. The gene for herbicide resistance may be used as a selectable marker and/or as a phenotypic trait. A single locus conversion of a site specific integration system allows for the integration of multiple genes at the converted loci.

Tissue Culture

Further reproduction of the variety can occur by tissue culture and regeneration. Tissue culture of various tissues of rice and regeneration of plants therefrom is well known and widely published. For example, reference may be had to Komatsuda, T., et al., Crop Sci., 31:333-337 (1991); Stephens, P. A., et al., Theor. Appl. Genet., 82:633-635 (1991); Komatsuda, T., et al., Plant Cell, Tissue and Organ Culture, 28:103-113 (1992); Dhir, S., et al., Plant Cell Reports, 11:285-289 (1992); Pandey, P., et al., Japan J. Breed., 42:1-5 (1992); and Shetty, K., et al., Plant Science, 81:245-251 (1992); as well as U.S. Pat. No. 5,024,944, issued Jun. 18, 1991 to Collins, et al., and U.S. Pat. No. 5,008,200, issued Apr. 16, 1991 to Ranch, et al. Thus, another aspect of this invention is to provide cells which upon growth and differentiation produce rice plants having the physiological and morphological characteristics of rice variety Taggart.

As used herein, the term “tissue culture” indicates a composition comprising isolated cells of the same or a different type or a collection of such cells organized into parts of a plant. Exemplary types of tissue cultures are protoplasts, calli, plant clumps, and plant cells that can generate tissue culture that are intact in plants or parts of plants, such as embryos, pollen, flowers, seeds, pods, leaves, stems, roots, root tips, anthers, and the like. Means for preparing and maintaining plant tissue culture are well known in the art. By way of example, a tissue culture comprising organs has been used to produce regenerated plants. U.S. Pat. Nos. 5,959,185; 5,973,234, and 5,977,445 describe certain techniques, the disclosures of which are incorporated herein by reference.

As used herein, the term “plant” includes plant cells, plant protoplasts, plant cells of tissue culture from which rice plants can be regenerated, plant calli, plant clumps, and plant cells that are intact in plants or parts of plants, such as pollen, flowers, embryos, ovules, seeds, pods, leaves, stems, pistils, anthers, and the like. Thus, another aspect of this invention is to provide for cells which upon growth and differentiation produce a cultivar having essentially all of the physiological and morphological characteristics of Taggart.

The present invention contemplates a rice plant regenerated from a tissue culture of a variety (e.g., Taggart) or hybrid plant of the present invention. As is well known in the art, tissue culture of rice can be used for the in vitro regeneration of a rice plant. Tissue culture of various tissues of rice and regeneration of plants therefrom is well known and widely published. For example, reference may be had to Chu, Q. R., et al., “Use of bridging parents with high anther culturability to improve plant regeneration and breeding value in rice,” Rice Biotechnology Quarterly, 38:25-26 (1999); Chu, Q. R., et al., “A novel plant regeneration medium for rice anther culture of Southern U.S. crosses,” Rice Biotechnology Quarterly, 35:15-16 (1998); Chu, Q. R., et al., “A novel basal medium for embryogenic callus induction of Southern US crosses,” Rice Biotechnology Quarterly, 32:19-20 (1997); and Oono, K., “Broadening the Genetic Variability By Tissue Culture Methods,” Jap. J. Breed., 33 (Suppl. 2), 306-307, illus. 1983. Thus, another aspect of this invention is to provide cells which upon growth and differentiation produce rice plants having the physiological and morphological characteristics of variety Taggart.

Duncan, et al., Planta, 165:322-332 (1985), reflects that 97% of the plants cultured that produced callus were capable of plant regeneration. Subsequent experiments with both cultivars and hybrids produced 91% regenerable callus that produced plants. In a further study in 1988, Songstad, et al., Plant Cell Reports, 7:262-265 (1988), reports several media additions that enhance regenerability of callus of two cultivars. Other published reports also indicated that “non-traditional” tissues are capable of producing somatic embryogenesis and plant regeneration. K. P. Rao, et al., Maize Genetics Cooperation Newsletter, 60:64-65 (1986), refers to somatic embryogenesis from glume callus cultures and B. V. Conger, et al., Plant Cell Reports, 6:345-347 (1987), indicates somatic embryogenesis from the tissue cultures of corn leaf segments. Thus, it is clear from the literature that the state of the art is such that these methods of obtaining plants are routinely used and have a very high rate of success.

Tissue culture of corn is described in European Patent Application Publication 160,390. Corn tissue culture procedures are also described in Green and Rhodes, “Plant Regeneration in Tissue Culture of Maize,” Maize for Biological Research, Plant Molecular Biology Association, Charlottesville, Va., 367-372 (1982), and in Duncan, et al., “The Production of Callus Capable of Plant Regeneration from Immature Embryos of Numerous Zea Mays Genotypes,” 165 Planta, 322:332 (1985). Thus, another aspect of this invention is to provide cells which upon growth and differentiation produce corn plants having the physiological and morphological characteristics of rice cultivar Taggart.

The utility of rice cultivar Taggart also extends to crosses with other species. Commonly, suitable species will be of the family Graminaceae, and especially of the genera Zea, Tripsacum, Croix, Schlerachne, Polytoca, Chionachne, and Trilobachne, of the tribe Maydeae.

This invention also is directed to methods for producing a rice plant by crossing a first parent rice plant with a second parent rice plant wherein the first or second parent rice plant is a rice plant of the variety Taggart. Further, both first and second parent rice plants can come from the rice variety Taggart. Thus, any such methods using the rice variety Taggart are part of this invention: selfing, backcrosses, hybrid production, crosses to populations, and the like. All plants produced using rice variety Taggart as a parent are within the scope of this invention, including those developed from varieties derived from rice variety Taggart. Advantageously, the rice variety could be used in crosses with other, different, rice plants to produce the first generation (F₁) rice hybrid seeds and plants with superior characteristics. The variety of the invention can also be used for transformation where exogenous genes are introduced and expressed by the variety of the invention. Genetic variants created either through traditional breeding methods using variety Taggart or through transformation of Taggart by any of a number of protocols known to those of skill in the art are intended to be within the scope of this invention.

The following describes breeding methods that may be used with cultivar Taggart in the development of further rice plants. One such embodiment is a method for developing a Taggart progeny rice plant in a rice plant breeding program comprising: obtaining the rice plant, or a part thereof, of cultivar Taggart utilizing said plant or plant part as a source of breeding material and selecting a Taggart progeny plant with molecular markers in common with Taggart and/or with morphological and/or physiological characteristics selected from the characteristics listed in Tables 2 or 3. Breeding steps that may be used in the rice plant breeding program include pedigree breeding, back crossing, mutation breeding, and recurrent selection. In conjunction with these steps, techniques such as RFLP-enhanced selection, genetic marker enhanced selection (for example SSR markers) and the making of double haploids may be utilized.

Another method involves producing a population of cultivar Taggart progeny rice plants, comprising crossing cultivar Taggart with another rice plant, thereby producing a population of rice plants, which, on average, derive 50% of their alleles from cultivar Taggart. A plant of this population may be selected and repeatedly selfed or sibbed with a rice cultivar resulting from these successive filial generations. One embodiment of this invention is the rice cultivar produced by this method and that has obtained at least 50% of its alleles from cultivar Taggart.

One of ordinary skill in the art of plant breeding would know how to evaluate the traits of two plant varieties to determine if there is no significant difference between the two traits expressed by those varieties. For example, see, Fehr and Walt, Principles of Cultivar Development, pp. 261-286 (1987). Thus the invention includes rice cultivar Taggart progeny rice plants comprising a combination of at least two Taggart traits selected from the group consisting of those listed in Tables 1, 2, 3, and 4, or the Taggart combination of traits listed in the Summary of the Invention, so that said progeny rice plant is not significantly different for said traits than rice cultivar Taggart as determined at the 5% significance level when grown in the same environment. Using techniques described herein, molecular markers may be used to identify said progeny plant as a Taggart progeny plant. Mean trait values may be used to determine whether trait differences are significant, and preferably the traits are measured on plants grown under the same environmental conditions. Once such a variety is developed its value is substantial since it is important to advance the germplasm base as a whole in order to maintain or improve traits such as yield, disease resistance, pest resistance, and plant performance in extreme environmental conditions.

Progeny of rice cultivar Taggart may also be characterized through their filial relationship with rice cultivar Taggart, as for example, being within a certain number of breeding crosses of rice cultivar Taggart. A breeding cross is a cross made to introduce new genetics into the progeny, and is distinguished from a cross, such as a self or a sib cross, made to select among existing genetic alleles. The lower the number of breeding crosses in the pedigree, the closer the relationship between rice cultivar Taggart and its progeny. For example, progeny produced by the methods described herein may be within 1, 2, 3, 4, or 5 breeding crosses of rice cultivar Taggart.

Pedigree Breeding

Pedigree breeding starts with the crossing of two genotypes, such as rice cultivar Taggart and another rice plant having one or more desirable characteristics that is lacking or which complements rice cultivar Taggart. If the two original parents do not provide all the desired characteristics, other sources can be included in the breeding population. In the pedigree method, superior plants are selfed and selected in successive filial generations. In the succeeding filial generations the heterozygous condition gives way to homogeneous varieties as a result of self-pollination and selection. Typically in the pedigree method of breeding, five or more successive filial generations of selfing and selection is practiced: F₁ to F₂; F₂ to F₃; F₃ to F₄; F₄ to F₅; etc. After a sufficient amount of inbreeding, successive filial generations will serve to increase seed of the developed variety. Preferably, the developed variety comprises homozygous alleles at about 95% or more of its loci.

In addition to being used to create a backcross conversion, backcrossing can also be used in combination with pedigree breeding. As discussed previously, backcrossing can be used to transfer one or more specifically desirable traits from one variety, the donor parent, to a developed variety called the recurrent parent, which has overall good agronomic characteristics yet lacks that desirable trait or traits. However, the same procedure can be used to move the progeny toward the genotype of the recurrent parent but at the same time retain many components of the nonrecurrent parent by stopping the backcrossing at an early stage and proceeding with selfing and selection. For example, a rice variety may be crossed with another rice variety to produce a first generation progeny plant. The first generation progeny plant may then be backcrossed to one of its parent varieties to create a BC₁ or BC₂. Progeny are selfed and selected so that the newly developed variety has many of the attributes of the recurrent parent and yet several of the desired attributes of the nonrecurrent parent. This approach leverages the value and strengths of the recurrent parent for use in new rice varieties.

Therefore, an embodiment of this invention is a method of making a backcross conversion of rice cultivar Taggart, comprising the steps of crossing a plant of rice cultivar Taggart with a donor plant comprising a desired trait, selecting an F₁ progeny plant comprising the desired trait, and backcrossing the selected F₁ progeny plant to a plant of rice cultivar Taggart. This method may further comprise the step of obtaining a molecular marker profile of rice cultivar Taggart and using the molecular marker profile to select for a progeny plant with the desired trait and the molecular marker profile of rice cultivar Taggart. In one embodiment the desired trait is a mutant gene or transgene present in the donor parent.

Recurrent Selection and Mass Selection

Recurrent selection is a method used in a plant breeding program to improve a population of plants. Rice cultivar Taggart is suitable for use in a recurrent selection program. The method entails individual plants cross pollinating with each other to form progeny. The progeny are grown and the superior progeny selected by any number of selection methods, which include individual plant, half-sib progeny, full-sib progeny and selfed progeny. The selected progeny are cross pollinated with each other to form progeny for another population. This population is planted and again superior plants are selected to cross pollinate with each other. Recurrent selection is a cyclical process and therefore can be repeated as many times as desired. The objective of recurrent selection is to improve the traits of a population. The improved population can then be used as a source of breeding material to obtain new varieties for commercial or breeding use, including the production of a synthetic cultivar. A synthetic cultivar is the resultant progeny formed by the intercrossing of several selected varieties.

Mass selection is a useful technique when used in conjunction with molecular marker enhanced selection. In mass selection seeds from individuals are selected based on phenotype or genotype. These selected seeds are then bulked and used to grow the next generation. Bulk selection requires growing a population of plants in a bulk plot, allowing the plants to self-pollinate, harvesting the seed in bulk and then using a sample of the seed harvested in bulk to plant the next generation. Also, instead of self pollination, directed pollination could be used as part of the breeding program.

Mutation Breeding

Mutation breeding is another method of introducing new traits into rice cultivar Taggart. Mutations that occur spontaneously or are artificially induced can be useful sources of variability for a plant breeder. The goal of artificial mutagenesis is to increase the rate of mutation for a desired characteristic. Mutation rates can be increased by many different means including temperature, long-term seed storage, tissue culture conditions, radiation; such as X-rays, Gamma rays (e.g., cobalt 60 or cesium 137), neutrons (product of nuclear fission by uranium 235 in an atomic reactor), Beta radiation (emitted from radioisotopes such as phosphorus 32 or carbon 14), or ultraviolet radiation (preferably from 2500 to 2900 nm), or chemical mutagens (such as base analogues (5-bromo-uracil), related compounds (8-ethoxy caffeine), antibiotics (streptonigrin), alkylating agents (sulfur mustards, nitrogen mustards, epoxides, ethylenamines, sulfates, sulfonates, sulfones, lactones), azide, hydroxylamine, nitrous acid, or acridines. Once a desired trait is observed through mutagenesis the trait may then be incorporated into existing germplasm by traditional breeding techniques. Details of mutation breeding can be found in “Principles of Cultivar Development,” Fehr, Macmillan Publishing Company (1993). In addition, mutations created in other rice plants may be used to produce a backcross conversion of rice cultivar Taggart that comprises such mutation.

Breeding with Molecular Markers

Molecular markers may be used in plant breeding methods utilizing rice cultivar Taggart.

Isozyme Electrophoresis and RFLPs have been widely used to determine genetic composition. See, for example, Dinka, S. J., et al., “Predicting the size of the progeny mapping population required to positionally clone a gene,” Genetics., 176(4):2035-54 (2007); Gonzalez, C., et al., “Molecular and pathogenic characterization of new Xanthomonas oryzae strains from West Africa,” Mol. Plant. Microbe Interact., 20(5):534-546 (2007); Jin, H., et al., “Molecular and cytogenic characterization of an Oryza officinalis-O. sativa chromosome 4 addition line and its progenies,” Plant Mol. Biol., 62(4-5):769-777 (2006); Pan, G., et al., “Map-based cloning of a novel rice cytochrome P450 gene CYP81A6 that confers resistance to two different classes of herbicides,” Plant Mol. Biol., 61(6):933-943 (2006); Huang, W., et al., “RFLP analysis for mitochondrial genome of CMS-rice,” Journal of Genetics and Genomics, 33(4):330-338 (2007); Yan, C. J., et al., “Identification and characterization of a major QTL responsible for erect panicle trait in japonica rice (Oryza sativa L.),” Theor. Appl. Genetics., DOI:10.1007/s00122-007-0635-9 (2007); and I. K. Vasil (ed.), DNA-based markers in plants, Kluwer Academic Press Dordrecht, the Netherlands.

SSR technology is currently the most efficient and practical marker technology; more marker loci can be routinely used and more alleles per marker locus can be found using SSRs in comparison to RFLPs. Gealy, David, et al., “Insights into the Parentage of Rice/red Rice Crosses Using SSR Analysis of US Rice Cultivars and Red Rice Populations,” Rice Technical Working Group Meeting Proceedings, Abstract, p. 179; Lawson, Mark J., et al., “Distinct Patterns of SSR Distribution in the Arabidopsis thaliana and rice genomes,” Genome Biology., 7:R14 (2006); Nagaraju, J., et al., “Genetic Analysis of Traditional and Evolved Basmati and Non-Basmati Rice Varieties by Using Fluorescence-based ISSR-PCR and SSR Markers,” Proc. Nat. Acad. Sci. USA., 99(9):5836-5841 (2002); and Lu, Hong, et al., “Population Structure and Breeding Patterns of 145 US Rice Cultivars Based on SSR Marker Analysis,” Crop Science, 45:66-76 (2005). Single Nucleotide Polymorphisms may also be used to identify the unique genetic composition of the invention and progeny varieties retaining that unique genetic composition. Various molecular marker techniques may be used in combination to enhance overall resolution.

Rice DNA molecular marker linkage maps have been rapidly constructed and widely implemented in genetic studies such as in Zhu, J. H., et al., “Toward rice genome scanning by map-based AFLP fingerprinting,” Mol. Gene. Genetics., 261(1):184-195 (1999); Cheng, Z., et al., “Toward a cytological characterization of the rice genome,” Genome Research., 11(12):2133-2141 (2001); Ahn, S., et al., “Comparative linkage maps of the rice and maize genomes,” Proc. Natl. Acad. Sci. USA, 90(17):7980-7984 (1993); and Kao, F. I., et al., “An integrated map of Oryza sativa L. chromosome 5,” Theor. Appl. Genet., 112(5):891-902 (2006). Sequences and PCR conditions of SSR Loci in rice as well as the most current genetic map may be found in RiceBLAST and the TIGR Rice Genome Annotation on the World Wide Web.

One use of molecular markers is Quantitative Trait Loci (QTL) mapping. QTL mapping is the use of markers, which are known to be closely linked to alleles that have measurable effects on a quantitative trait. Selection in the breeding process is based upon the accumulation of markers linked to the positive effecting alleles and/or the elimination of the markers linked to the negative effecting alleles from the plant's genome.

Molecular markers can also be used during the breeding process for the selection of qualitative traits. For example, markers closely linked to alleles or markers containing sequences within the actual alleles of interest can be used to select plants that contain the alleles of interest during a backcrossing breeding program. The markers can also be used to select for the genome of the recurrent parent and against the genome of the donor parent. Using this procedure can minimize the amount of genome from the donor parent that remains in the selected plants. It can also be used to reduce the number of crosses back to the recurrent parent needed in a backcrossing program. The use of molecular markers in the selection process is often called genetic marker enhanced selection. Molecular markers may also be used to identify and exclude certain sources of germplasm as parental varieties or ancestors of a plant by providing a means of tracking genetic profiles through crosses.

Production of Double Haploids

The production of double haploids can also be used for the development of plants with a homozygous phenotype in the breeding program. For example, a rice plant for which rice cultivar Taggart is a parent can be used to produce double haploid plants. Double haploids are produced by the doubling of a set of chromosomes (1N) from a heterozygous plant to produce a completely homozygous individual. For example, see, Wan, et al., “Efficient Production of Doubled Haploid Plants Through Colchicine Treatment of Anther-Derived Maize Callus,” Theoretical and Applied Genetics, 77:889-892 (1989), and U.S. Pat. No. 7,135,615.

Methods for obtaining haploid plants are also disclosed in Kobayashi, M., et al., Journ. of Heredity, 71(1):9-14 (1980), Pollacsek, M., 12(3):247-251, Agronomie, Paris (1992); Cho-Un-Haing, et al., Journ. of Plant Biol., 39(3):185-188 (1996); Verdoodt, L., et al., 96(2):294-300 (February 1998); Genetic Manipulation in Plant Breeding, Proceedings International Symposium Organized by EUCARPIA, Berlin, Germany (Sep. 8-13, 1985); Thomas, W J K, et al., “Doubled haploids in breeding,” in Doubled Haploid Production in Crop Plants, Maluszynski, M., et al. (Eds.), Dordrecht, The Netherland Kluwer Academic Publishers, pp. 337-349 (2003).

Descriptions of other breeding methods that are commonly used for different traits and crops can be found in one of several reference books (e.g., Allard (1960); Simmonds (1979); Sneep, et al. (1979); Fehr (1987)).

The seed of rice cultivar Taggart, the plant produced from the cultivar seed, the hybrid rice plant produced from the crossing of the cultivar, hybrid seed, and various parts of the hybrid rice plant and transgenic versions of the foregoing, can be utilized for human food, livestock feed, and as a raw material in industry.

The present invention provides methods for producing an herbicide-resistant rice plant through conventional plant breeding involving sexual reproduction. The methods comprise crossing a first rice plant that is a plant of rice cultivar Taggart to a second rice plant that is not resistant to an herbicide. The methods of the invention can further involve one or more generations of backcrossing the progeny rice plants of the first cross to a rice plant of the same line or genotype as either the first or second rice plant. Alternatively, the progeny of the first cross or any subsequent cross can be crossed to a third rice plant that is of a different line or genotype than either the first or second rice plant. The methods of the invention can additionally involve selecting rice plants that comprise the herbicide tolerance characteristics of the first rice plant.

The present invention further provides methods for increasing the herbicide-resistance of a rice plant, particularly an herbicide-resistant rice plant, through conventional plant breeding involving sexual reproduction. The methods comprise crossing a first rice plant that is a plant of rice cultivar Taggart to a second rice plant that may or may not be resistant to the same herbicides as the plant of rice cultivar Taggart or may be resistant to different herbicide or herbicides than the first rice plant. The progeny rice plants produced by this method of the present invention have increased resistance to an herbicide when compared to either the first or second rice plant or both. When the first and second rice plants are resistant to different herbicides, the progeny plants will have the combined herbicide tolerance characteristics of the first and second rice plants. The methods of the invention can further involve one or more generations of backcrossing the progeny rice plants of the first cross to a rice plant of the same line or genotype as either the first or second rice plant. Alternatively, the progeny of the first cross or any subsequent cross can be crossed to a third plant that is of a different line or genotype than either the first or second plant. The methods of the invention can additionally involve selecting rice plants that comprise the herbicide tolerance characteristics of the first rice plant, the second rice plant, or both the first and the second rice plants.

TABLES

Yield and Grain Characteristics for Rice Cultivar Taggart

In Table 2, agronomic characteristics are shown for rice cultivar Taggart and for seven other rice cultivars. These data are the result of the Arkansas Rice Performance Trials (ARPT) conducted in 2006. (Stuttgart, Rice Research and Extension Center (RREC); Colt, Pine Tree Experiment Station (PTES); Keiser, Northeast Research and Extension Center (NEREC); Rohwer, Southeast Research and Extension Center Rohwer Division (SEREC-RD); Clay Co. and Jackson Co.). Column one shows the variety, column two shows the yield in bushels per acre, column three shows the plant height in inches, column four shows the maturity in days at 50% heading, column five shows the kernel weight in milligrams and column six shows the milling percent head rice (or whole kernel rice) as compared to the percent of total milled rice.

TABLE 2 Kernel Yield Height Maturity weight Milling Variety (BU/AC) (IN.) (50% HD) (mg) HR:TOT Taggart 204 44 94 19.8 60:71 Templeton 197 41 94 16.1 60:71 Francis 208 40 90 16.9 59:70 Wells 198 42 91 18.6 56:71 LaGrue 197 44 92 17.8 58:70 Cybonnet 186 38 90 17.5 62:71 Cocodrie 162 37 91 17.7 62:71 Drew 168 40 92 17.0 62:70 C.V._(.05) 9.2

In Table 3, agronomic characteristics are shown for rice cultivar Taggart and for seven other rice cultivars. These data are the result of the Arkansas Rice Performance Trials (ARPT) conducted in 2007. (Stuttgart, RREC; Keiser, NEREC; Rohwer, SEREC-RD; Clay Co. and Jackson Co.). Column one shows the variety, column two shows the yield in bushels per acre, column three shows the plant height in inches, column four shows the maturity in days at 50% heading, column five shows the kernel weight in milligrams and column six shows the milling percent head rice (or whole kernel rice) as compared to the percent of total milled rice.

TABLE 3 Kernel Yield Height Maturity weight Milling Variety (BU/AC) (IN.) (50% HD) (mg) HR:TOT Taggart 190 45 92 19.6 50:70 Templeton 179 41 90 16.0 51:70 Francis 185 38 87 17.2 53:70 Wells 185 41 88 18.7 48:70 LaGrue 186 45 90 17.5 52:69 Cybonnet 171 35 89 17.8 58:71 Cocodrie 163 36 88 17.9 61:70 Drew 175 44 91 16.0 53:69 C.V._(.05) 10.3

In Table 4, agronomic characteristics are shown for rice cultivar Taggart and for seven other rice cultivars. These data are the result of the Arkansas Rice Performance Trials (ARPT) conducted in 2008. (Stuttgart, RREC; Colt, PTES; Keiser, NEREC; Rohwer, SEREC-RD; Clay Co. and Jackson Co.). Column one shows the variety, column two shows the yield in bushels per acre, column three shows the plant height in inches, column four shows the maturity in days at 50% heading, column five shows the kernel weight in milligrams and column six shows the milling percent head rice (or whole kernel rice) as compared to the percent of total milled rice.

TABLE 4 Kernel Yield Height Maturity weight Milling Variety (BU/AC) (IN.) (50% HD) (mg) HR:TOT Taggart 165 44 98 20.8 60:72 Templeton 156 41 95 16.3 57:70 Francis 170 39 92 17.4 62:72 Wells 165 40 94 19.0 56:72 LaGrue 161 44 95 18.0 56:70 Cybonnet 144 37 92 17.6 63:72 Cocodrie 148 36 89 17.7 63:72 Drew 139 43 96 15.8 60:71 C.V._(.05) 12.1

In Table 4, agronomic characteristics are shown for rice cultivar Taggart and for seven other rice cultivars. These data are the average results of the Arkansas Rice Performance Trials (ARPT) conducted from 2006 to 2008 (an average of Tables 2 to 4). Column one shows the variety, column two shows the yield in bushels per acre, column three shows the plant height in inches, column four shows the maturity in days at 50% heading, column five shows the kernel weight in milligrams and column six shows the milling percent head rice (or whole kernel rice) as compared to the percent of total milled rice.

TABLE 5 Kernel Yield Height Maturity weight Milling Variety (BU/AC) (IN.) (50% HD) (mg) HR:TOT Taggart 187 44 94 20.1 57:71 Templeton 179 41 93 16.1 56:71 Francis 189 39 90 17.1 58:71 Wells 184 41 91 18.8 54:71 LaGrue 182 44 92 17.8 56:70 Cybonnet 168 37 90 17.6 61:71 Cocodrie 158 36 89 17.8 62:71 Drew 161 42 93 16.3 58:70

In Table 6, agronomic characteristics are shown for rice cultivar Taggart, and seven other rice cultivars. The data are the result of trials at the Arkansas Rice Performance Trials (ARPT) from 2006. Column 1 shows the variety, columns 2 to 7 give the average grain yield for each of 6 different locations for each variety in bushels per acre, column 8 gives the average grain yield for the six locations, columns 9 to 14 show the average head rice (%) to total rice (%) ratio for each of 6 different locations and column 15 shows the average head rice (%) to total rice (%) ratio for the six locations.

TABLE 6 Grain Yield (BU/AC) Head Rice (%):Total Rice (%) Variety RREC PTES NEREC SEBES CC JC AVE RREC PTES NEREC SEREC CC JC AVE Taggart 186 182 218 149 231 260 204 62:72 62:71 60:69 63:74 60:70 54:69 60:71 Templeton 183 206 204 158 195 235 197 65:71 65:71 57:68 55:77 59:71 58:69 60:71 Francis 207 199 215 184 205 237 208 63:72 62:69 57:68 65:74 60:70 51:67 59:70 Wells 166 205 205 146 233 235 198 63:72 62:72 55:69 60:75 61:72 43:68 56:71 LaGrue 179 193 180 169 218 241 197 64:71 59:69 56:68 61:74 61:70 52:67 58:70 Cybonnet 162 178 197 133 221 228 186 65:71 68:72 61:69 63:75 63:71 58:69 62:71 Cocodrie 182 159 176 142 103 210 162 66:72 65:72 60:70 69:75 62:70 55:68 62:71 Drew 162 166 179 108 186 206 168 62:71 67:71 60:68 60:74 59:67 63:69 62:70 C.V._(.05) 9.3 9.6 7.6 9.9 11.0 7.6 9.2

In Table 7, agronomic characteristics are shown for rice cultivar Taggart, and seven other rice cultivars. The data are the result of trials at the Arkansas Rice Performance Trials (ARPT) from 2007. Column 1 shows the variety, columns 2 to 7 give the average grain yield for each of 6 different locations for each variety in bushels per acre, column 8 gives the average grain yield for the six locations, columns 9 to 14 show the average head rice (%) to total rice (%) ratio for each of 6 different locations and column 15 shows the average head rice (%) to total rice (%) ratio for the six locations.

TABLE 7 Grain Yield (BU/AC) Head Rice (%):Total Rice (%) Variety RREC PTES NEREC SEBES CC JC AVE RREC PTES NEREC SEREC Taggart 187 149 144 215 255 190 57:72 47:69 48:71 50:70 50:72 Templeton 163 128 158 207 237 179 57:71 48:67 55:70 45:71 51:70 Francis 199 93 163 218 249 185 62:72 43:68 57:71 55:71 53:70 Wells 172 168 150 203 230 185 54:72 33:66 52:72 53:72 48:70 LaGrue 162 140 181 203 242 186 56:70 47:66 52:69 55:70 52:69 Cybonnet 163 190 103 190 207 171 63:72 51:68 61:71 60:72 58:71 Cocodrie 176 144 95 162 238 163 62:72 58:69 62:70 63:71 61:70 Drew 167 153 148 216 191 175 51:69 49:67 59:70 50:71 53:69 C.V._(.05) 5.3 16.2 13.6 8.4 7.8 10.3

In Table 8, agronomic characteristics are shown for rice cultivar Taggart, and seven other rice cultivars. The data are the result of trials at the Arkansas Rice Performance Trials (ARPT) from 2008. Column 1 shows the variety, columns 2 to 7 give the average grain yield for each of 6 different locations for each variety in bushels per acre, column 8 gives the average grain yield for the six locations, columns 9 to 14 show the average head rice (%) to total rice (%) ratio for each of 6 different locations and column 15 shows the average head rice (%) to total rice (%) ratio for the six locations.

TABLE 8 Grain Yield (BU/AC) Head Rice (%):Total Rice (%) Variety RREC PTES NEREC SEBES CC JC AVE RREC PTES NEREC Taggart 194 181 145 125 181 165 61:69 60:72 60:73 60:72 Templeton 184 156 181 130 127 156 64:71 59:71 49:69 57:70 Francis 196 167 187 138 163 170 63:70 59:71 64:74 62:72 Wells 194 177 172 151 133 165 66:74 60:72 45:71 56:72 LaGrue 171 162 158 167 147 161 65:70 54:69 51:69 56:70 Cybonnet 173 136 177 116 120 144 68:73 65:71 59:74 63:72 Cocodrie 158 150 173 117 144 148 66:71 67:74 58:72 63:72 Drew 162 161 146 97 129 139 67:73 58:70 57:71 60:71 C.V._(.05) 5.4 7.7 13.6 11.9 12.6 12.1

In Table 9, agronomic characteristics are shown for rice cultivar Taggart, and seven other rice cultivars. The data are the result of and average of the trials at the Arkansas Rice Performance Trials (ARPT) from 2006 to 2008. Column 1 shows the variety, columns 2 to 7 give the average grain yield for each of 6 different locations for each variety in bushels per acre, column 8 gives the average grain yield for the six locations, columns 9 to 14 show the average head rice (%) to total rice (%) ratio for each of 6 different locations and column 15 shows the average head rice (%) to total rice (%) ratio for the six locations.

TABLE 9 Grain Yield (BU/AC) Head Rice (%):Total Rice (%) Variety RREC PTES* NEREC SEBES CC** JC AVE RREC NEREC CC** JC AVE*** Taggart 189 182 171 139 223 232 187 60:71 56:70 54:71 55:71 57:71 Templeton 177 181 171 149 201 200 179 62:71 55:69 57:71 51:70 56:71 Francis 201 183 165 162 212 216 189 63:71 53:69 59:71 57:71 58:71 Wells 177 191 182 149 218 199 184 61:73 49:69 57:72 47:70 54:71 LaGrue 171 178 159 172 211 210 182 62:70 52:68 57:70 53:69 56:70 Cybonnet 166 157 188 117 206 185 168 65:72 59:69 62:71 59:72 61:71 Cocodrie 172 155 164 118 133 197 158 65:72 62:71 62:70 59:70 62:71 Drew 164 164 159 118 201 175 161 60:71 56:68 59:69 57:70 58:70 *PTES data from 2006 & 2008 **CC data from 2006-2007 ***AVE includes the 2006 milling data from PTES and SEBES

In Table 10, agronomic characteristics are shown for rice cultivar Taggart, and five other rice cultivars. The data are the result of trials at the Arkansas Uniform Regional Rice Nursery (URRN) from in 2007. Column 1 shows the variety, column 2 shows the grain yield each variety in bushels per acre, column 3 shows the plant height in inches, column 4 shows the maturity in days at 50% heading, column 5 shows the kernel weight in milligrams and columns 6 shows the milling percent head rice (or whole kernel rice) as compared to the percent of total milled rice.

TABLE 10 Kernel Yield Height Maturity Weight Milling Variety (BU/AC) (IN.) (50% HD) (MG) HR:TOT Taggart 193 45 100 19.4 57:70 Templeton 187 42 98 18.1 59:68 Francis 201 41 95 18.1 64:70 Wells 177 41 97 19.9 55:70 Cybonnet 176 40 94 18.7 65.70 Cocodrie 205 40 93 18.3 62:70

In Table 11, agronomic characteristics are shown for rice cultivar Taggart, and five other rice cultivars. The data are the result of trials at the Arkansas URRN from in 2008. Column 1 shows the variety, column 2 shows the grain yield each variety in bushels per acre, column 3 shows the plant height in inches, column 4 shows the maturity in days at 50% heading, column 5 shows the kernel weight in milligrams and columns 6 shows the milling percent head rice (or whole kernel rice) as compared to the percent of total milled rice.

TABLE 11 Kernel Yield Height Maturity Weight Milling Variety (BU/AC) (IN.) (50% HD) (MG) HR:TOT Taggart 185 42 95 22.0 58:70 Templeton 187 38 94 18.0 59:70 Francis 177 40 90 18.0 61:70 Wells 174 39 93 21.1 54:68 Cybonnet 160 36 93 18.4 65:71 Cocodrie 163 36 89 18.7 56:68

In Table 12, agronomic characteristics are shown for rice cultivar Taggart, and five other rice cultivars. The data are the average of results of trials at the Arkansas URRN from 2007 to 2008. Column 1 shows the variety, column 2 shows the grain yield each variety in bushels per acre, column 3 shows the plant height in inches, column 4 shows the maturity in days at 50% heading, column 5 shows the kernel weight in milligrams and columns 6 shows the milling percent head rice (or whole kernel rice) as compared to the percent of total milled rice.

TABLE 12 Kernel Yield Height Maturity Weight Milling Variety (BU/AC) (IN.) (50% HD) (MG) HR:TOT Taggart 189 44 98 20.7 58:70 Templeton 187 40 96 18.1 59:69 Francis 189 41 93 18.1 63:70 Wells 176 40 95 20.5 55:69 Cybonnet 168 38 94 18.6 65:71 Cocodrie 184 38 91 18.5 59:69

In Table 13, agronomic characteristics are shown for rice cultivar Taggart and five other rice cultivars. The data are the results of a trial at the Arkansas URRN in 2006. Column 1 shows the variety, columns 2 to 4 give the average grain yield for each of 3 different locations for each variety in bushels per acre, column 5 shows the average of all locations of grain yield for each variety, columns 6 to 9 shows the average head rice (%) to total rice (%) ratio for each of 3 different locations and column 10 shows the average of all locations of head rice (%) to total rice (%) ratio for each variety.

TABLE 13 Grain Yield (BU/AC) Head Rice(%):Total Rice(%) Variety LA MS TX AVE LA MS TX AVE Taggart 218 203 180 200 60:71 55:72 53:71 56:71 Templeton 169 256 203 209 62:67 64:71 58:68 61:69 Francis 230 233 190 217 58:66 57:66 55:67 57:66 Wells 219 270 194 228 57:67 62:71 58:71 59:70 Cybonnet 202 191 180 191 63:69 60:68 68:74 64:70 Cocodrie 188 222 194 201 60:68 59:68 58:72 59:69

In Table 14, agronomic characteristics are shown for rice cultivar Taggart and five other rice cultivars. The data are the results of a trial at the Arkansas URRN in 2007. Column 1 shows the variety, columns 2 to 6 give the average grain yield for each of 5 different locations for each variety in bushels per acre, column 7 shows the average of all locations of grain yield for each variety, columns 8 to 10 shows the average head rice (%) to total rice (%) ratio for each of 3 different locations and column 11 shows the average of all locations of head rice (%) to total rice (%) ratio for each variety.

TABLE 14 Grain Yield (BU/AC) Head Rice(%):Total Rice(%) Variety AR LA MO MS TX AVE AR LA TX AVE Taggart 193 171 185 189 270 202 57:70 58:70 59:74 58:71 Templeton 187 147 162 224 185 181 59:68 66:71 54:68 60:69 Francis 201 195 166 229 192 197 64:70 63:71 51:65 59:69 Wells 177 144 177 216 194 182 55:70 60:72 49:67 55:70 Cybonnet 176 172 178 195 152 175 65:70 66:72 65:73 65:72 Cocodrie 205 171 200 197 158 186 62:70 63:71 52:69 59:70

In Table 15, agronomic characteristics are shown for rice cultivar Taggart and five other rice cultivars. The data are the results of a trial at the Arkansas URRN in 2008. Column 1 shows the variety, columns 2 to 6 give the average grain yield for each of 5 different locations for each variety in bushels per acre, column 7 shows the average of all locations of grain yield for each variety, columns 8 to 10 shows the average head rice (%) to total rice (%) ratio for each of 3 different locations and column 11 shows the average of all locations of head rice (%) to total rice (%) ratio for each variety.

TABLE 15 Grain Yield (BU/AC) Head Rice(%):Total Rice(%) Variety AR LA MO MS TX AVE AR LA TX AVE Taggart 185 244 184 214 253 216 58:70 57:70 48:68 54:69 Templeton 187 185 147 184 226 186 59:70 61:69 53:68 58:69 Francis 177 228 167 222 200 199 61:70 59:68 45:65 55:68 Wells 174 248 148 197 234 200 54:68 57:68 51:69 54:68 Cybonnet 160 205 181 176 223 189 65:71 66:72 54:67 62:70 Cocodrie 163 216 159 209 225 194 56:68 62:70 54:68 57:69

In Table 16, agronomic characteristics are shown for rice cultivar Taggart and five other rice cultivars. The data are the averages of results of trials at the Arkansas URRN from 2006 to 2008. Column 1 shows the variety, columns 2 to 6 give the average grain yield for each of 5 different locations for each variety in bushels per acre, column 7 shows the average of all locations of grain yield for each variety, columns 8 to 10 shows the average head rice (%) to total rice (%) ratio for each of 3 different locations and column 11 shows the average of all locations of head rice (%) to total rice (%) ratio for each variety.

TABLE 16 Grain Yield (BU/AC) Head Rice(%):Total Rice(%) Variety AR* LA MO* MS TX AVE AR* LA MS** TX*** AVE Taggart 189 211 185 202 234 207 58:70 58:70 52:70 56:73 56:71 Templeton 187 166 155 221 205 189 59:69 63:69 59:70 56:68 60:69 Francis 189 218 167 228 194 202 63:70 60:68 51:66 53:66 57:68 Wells 176 204 163 228 207 199 55:69 58:69 57:70 54:69 56:69 Cybonnet 168 193 180 187 185 184 65:71 65:71 57:68 67:74 64:71 Cocodrie 184 192 180 209 192 193 59:69 62:70 57:68 55:71 58:70 *AR & MO data from 2007-2008

In Table 17, kernel characteristics are shown for rice cultivars Taggart and Templeton. The data are averages of the following trials, 2007 ARPT RREC, 2007 Breeder Head Row Seed RREC, 2007 Stuttgart Initial Test Group 5 and 2008 Stuttgart Initial Test Groups 4, 5 and 6. Column 1 shows the variety, column 2 shows the class, column 3 shows the length in centimeters, column 4 shows the width in centimeters, column 5 shows the thickness in centimeters, column 6 shows the length to width ratio and column 7 shows the kernel weight in milligrams.

TABLE 17 Kernel Variety Class Length Width Thickness L/W Weight Taggart Rough 9.62 2.58 2.05 3.73 25.9 Templeton Rough 9.24 2.36 1.95 3.92 21.8 Taggart Brown 7.59 2.29 1.79 3.31 21.2 Templeton Brown 7.16 2.11 1.73 3.40 17.7 Taggart Milled 7.22 2.28 1.74 3.17 19.7 Templeton Milled 6.65 2.10 1.67 3.17 16.2 Disease Evaluations for Rice Cultivar Taggart

Rice diseases are usually rated visually on a 0-9 scale to estimate degree of severity. Numerical data is often converted to this scale. A rating of zero indicates complete disease immunity. A rating of one to three indicates resistance where little loss occurs and in the case of rice blast pathogen growth is restricted considerably. Conversely, a nine rating indicates maximum disease susceptibility, which typically results in complete plant death and/or yield loss. Depending upon the disease in question, a disease rating of four to six is usually indicative of acceptable disease resistance under conditions slightly favoring the pathogen. Numerical ratings are sometimes converted to letter symbols where 0-3=R (resistant), 3-4=MR (moderately resistant), 5-6=MS (moderately susceptible) 7=S (susceptible) and 8-9 VS (very susceptible). Exceptions to established ratings do occur unexpectedly as disease situations change.

Greenhouse blast tests are the primary means of screening large number of entries for varietal reaction to the many blast races occurring in the production areas. Although results are quite variable and testing conditions tends to overwhelm any field resistance present in the entry, this test provides an accurate definition of the fungus-variety genetics. Blast field nurseries, utilizing both natural and lab produced inoculum, are established in an effort to better define blast susceptibility under field conditions. Since field nursery is also quite variable, new techniques are currently being developed and evaluated to better estimate cultivar field resistance to blast.

Table 18 is a summary of available leaf blast rating data^(a) from Taggart and six comparison plants inoculated with the indicated race using standard greenhouse techniques.^(b) Data were taken from 2005 to 2008. Column 1 shows the variety and columns 2 to 17 show leaf blast rating data of each race for each variety.

TABLE 18 IB- IB- IC- IC- IE- IE- IB- IB- Variety IB-1 IB-1 49 49 17 17 IE-1 IE-1 IG-1 IG-1 IH-1 IH-1 1K 1K 33 33 Taggart 5 S 5 S 6 S 6 S 7 S 6 S  3^(d) 7 S Templeton 1 R 0 R 0 R 0 R 0 R 0 R  2^(c) MR- 7 S MS Banks 2 R 1 R 0 R 0 R 1 R 1 R 7 S 8 S Cybonnet 1 R 0 R 0 R 0 R 0 R 0 R 6 S 6 S Drew 1 R 0 R 0 R 0 R 0 R 0 R 6 S 6 S Francis 6 S 7 S 8 S 6 S 7 S 1 S 6 S 7 S Wells 7 S 7 S 7 S 7 S 2 S 0 S 6 S 7 S ^(a)Standard visual rating scale 0-9 where 0 = resistant and 9 = very susceptible. ^(b)Plants in the 3-r leaf growth stage were sprayed with spore suspension, held in moist chamber 12-18 hours then moved to greenhouse conditions. ^(c)Mean value of variable data presented. Ratings from seven tests were less than zero (R). However, mean ratings from four additional tests was 4.5 (S). Entry may likely to be susceptible to this race in moisture stress conditions. ^(d)Mean value of variable data presented. Ratings from four tests were less than two (R). However, mean ratings from one additional tests was 6 (S). Data are insufficient to accurately indicate susceptibility to this race.

Table 19 is a summary of available blast rating data^(a) from upland field blast nurseries inoculated using standard techniques^(b) for Taggart and five comparison varieties. Data were taken from 2005 to 2008. Column 1 shows the variety name, columns 2 to 3 show the PTES Panicle Blast Rating and columns 4 to 5 show the PTES Leaf Blast Rating.

TABLE 19 PTES Panicle PTES Panicle PTES Leaf PTES Leaf Variety Blast Rating Blast Rating Blast Rating Blast Rating Taggart 4 S-MS 3.7 S Templeton 2 R 0.9 R Banks 3.7 R 0.5 R Cybonnet 2.7 R 1.3 R Francis 7.5 S 6 S Wells 6.1 S 5.6 S ^(a)Standard visual rating scale 0-9 where 0 = resistant (S) and 9 = very susceptible (VS). Leaf blast ratings were made on plants soon after inoculation. Panicle blast ratings were made at or near grain fill. ^(b)Upland nursery plants in 4-6 leaf growth stage were artificially inoculated with multiple races IB-1, IB-49, IC-17, IE-1, IH-1, and IG-1 growing on rye grass seed. Plots were flooded as necessary with plants being drought stressed during the growing season, particularly after panicle exsertion.

Table 20 is a summary of available Sheath Blight rating data^(a) for Taggart and five comparison varieties from field nurseries inoculated using standard techniques^(b). Data were taken from 2005 to 2008.

TABLE 20 Mean Overall Range of Overall Variety Numerical Rating Ratings Rating Taggart 5.5 4-7 S Templeton 5.8 5-7 S Banks 5.8 5-7 S Cybonnet 7   6-8 VS Drew 6.1 5-7 S Francis 6.5 6-8 S-VS Wells S S S ^(a)Standard visual rating scale 0-9 where 0 = resistant (R) and 9 = very susceptible (VS). Standard sheath blight ratings were made after grain fill as plants neared maturity. ^(b)Nursery plants growing under typical flood irrigation were artificially inoculated at or near beginning internode elongation with the pathogen growing on corn and rye grass seed.

Tables 21 and 22 are a summary of rice variety reactions¹ to diseases from the ARPT fact sheet (2009).

For Table 21, column 1 shows the variety or hybrid name, column 2 shows the reaction to Sheath Blight, column 3 shows the reaction to Blast, column 4 shows the reaction to Straighthead, column 5 shows the reaction to Bacterial Panicle Blight and column 6 shows the reaction to Narrow Brown Leaf Spot.

For Table 22, column 1 shows the variety name or hybrid, column 2 shows the reaction to Stem Rot, column 3 shows the reaction to Kernel Smut, column 4 shows the reaction to False Smut, column 5 shows the reaction to Brown Smut and column 6 shows the lodging score.

TABLE 21 Bacterial Narrow Sheath Panicle Brown Variety/Hybrid Blight Blast² Straighthead Blight Leaf Spot Taggart MS S MS MS Bengal MS S VS VS S Bowman MS S MS S MR Catahoula S R S MS* MR Cheniere S S MS MS* VS* CL 131 VS MS VS VS VS CL 151 S VS VS S S CL 171AR VS S MS S MS CL 161 VS S MS S MS Cocodrie S MS VS VS MS Cybonnet VS R MS S MS Francis MS VS MS VS S Jupiter MS MS MS R MS KDM 08 MS MS S Neptune MS R MS R* MS Presidio S MS MS Rondo MR R S MR RT CL XL 745 MS R MR MS RT CL XL729 MS MR MR MR MS RT CL XL730 MS MR MR MR MS RT XL 744 MS R MR MS RT XL723 MS R MR MR MS Templeton MS R MS MS Sabine S S MS Sierra MS VS MS MS MS Spring S MS VS S MS Trenasse VS S VS S S

TABLE 22 Stem Kernel Variety/Hybrid Rot³ Smut False Smut Brown Spot Lodging Taggart S S S R MS Bengal VS MS MS VS MR Bowman S S S R MR Catahoula S S S R MR Cheniere S S S R MR CL 131 S S S R R CL 151 S S S R MS CL 171AR S S S R MS CL 161 S S S R MS Cocodrie S S S R MR Cybonnet S S S R MR Francis S VS S R MS Jupiter S MS MS R MR KDM 08 S MS R MS Neptune S MS MS MR Presidio S S S R MR Rondo MS MS VS R S RT CL XL 745 MS MS S R S RT CL XL729 MS MS S R S RT CL XL730 MS MS S R S RT XL 744 MS MS S R S RT XL723 MS MS S R MS Templeton S S S R MS Sabine S S S R MR Sierra S S S R MR Spring VS MS MS R S Trenasse S S S R MS ¹Reaction: R = Resistant; MR = Moderately Resistant; MS = Moderately Susceptible; S = Susceptible; VS = Very Susceptible. Reactions were determined based on historical and recent observations from test plots and in grower fields across Arkansas. In general, these reactions would be expected under conditions that favor severe disease development including excessive nitrogen rates (most diseases) or low flood depth (blast). ²Based on reaction to common races of the rice blast fungus in Arkansas for the most part; however, Banks and other Pi-ta resistant gene based varieties are susceptible to Race IE-1k, a previously rare race that has increased in importance in the state since 2004. All rice varieties should be monitored periodically for blast since the blast fungus is capable of developing new races that can overcome known resistance genes. ³Other Notes: Most cultivars will be susceptible to stem rot under low K and high N conditions. Bengal and certain other cultivars become very susceptible to brown spot under low K conditions. Most cultivars are susceptible to false smut under high N, late planted conditions. Kernel smut is increased by excessive nitrogen fertilization. Kernel Discolor Evaluations of Rice Cultivar Taggart

An increasingly important aspect of rice quality is the level of discolored kernels. In the field, kernel discolorations are caused by: (1) fungi alone, (2) fungi introduced through feeding probes of insects, and (3) physiological responses to adverse environmental conditions during grain fill. Infection by kernel smut, brown spot, or other fungi alone often cause black, brown, red, or pink discolored kernels. Rice stink bug adults and nymphs commonly are found in all Arkansas rice fields and feed on rice kernels at all stages of development except at hard dough and maturity. Very often because the hull is pierced by rice stink bugs fungi gain entry and the infection results in discolored and chalky kernels. Another cause of discolored kernels is apparently physiological and has been called linear discolored kernels. Linear discolored kernels have a straight (linear) “cut” in the kernel that is surrounded by a dark brown to black area. All agents that discolor rice kernels are commonly found in all Arkansas rice fields. However, local environmental conditions control the level to which any one of the agents infest rice and rice varieties have different levels of susceptibility. Regardless of the cause, discolored kernels are costly to growers and millers.

Table 23 is a summary of data taken in 2006 from URRN trials in Stuttgart, Arkansas. Column 1 shows the variety name, column 2 shows the susceptibility to rice stink bug, column 3 shows the susceptibility to kernel smut, column 4 shows the susceptibility to other damage—all other discolorations that are not caused by one of the other four reasons, column 5 shows linear damage—non-insect caused discolored kernels (linear discolored kernels have a straight or linear “cut” in the kernel that is surrounded by a dark brown to black area. The black color cannot be removed by milling) and column 6 shows the susceptibility to false smut. A sample of 200 g to 250 g of rough rice from each replication is screened visually for each of these discolorations and the number of grains which have each trait are recorded.

TABLE 23 Name Rice Stink Bug Kernel Smut Other Linear False Smut Taggart 3.29 0.009 0.54 0.036 0 CPRS 2.20 0.014 0.49 0.005 0 XP723 1.64 0 0.32 0 0 Evaluations of Rice Cultivar Taggart to Straighthead

Straighthead is a physiological disorder which appears to be effected by the oxygen potential of the soil. Under certain conditions, arsenic levels can increase in these soils or on soils where cotton has been grown and MSMA or other arsenical pesticides have been applied. Straighthead may also occur in soils high in organic matter. Symptoms can only be detected after panicle emerge and fail to produce grain. Foliage tends to remain dark green. Rice grains may be distorted especially on long-grain varieties forming a parrot-beak on the end of the hull. Floral parts may also be missing and under sever conditions panicle fail to emerge from the boot.

In Table 24, the reaction of Taggart to Straighthead is compared to various rice cultivars in three separate trials from 2006, 2007 and 2008. Column 2 shows the variety name, columns 3 to 5 show the rep 1, rep 2 and rep 3, respectively and column 6 shows the mean of reps 1 to 3.

TABLE 24 VARIETY REP 1 REP 2 REP 3 MEAN 2006 Straighthead Templeton 7 9 9 8.3 URRN and ARPT¹ Taggart 5 7 6.0 PI 636726 3 5 0 2.7 Wells 5 7 7 6.3 Templeton 9 9 9 9.0 Taggart 5 7 5 5.7 Cybonnet 5 7 7 6.3 Wells 7 7 7 7.0 2007 Straighthead Templeton 6 7 7 6.7 URRN and ARPT Taggart 5 5 5.0 RU0001124 5 5 6 5.3 Wells 7 6 5 6.0 Templeton 7 7 7 7.0 Taggart 6 4 5 5.0 Cybonnet 3 3 5 3.7 Wells 6 6 7 6.3 2008 Straighthead Templeton 7 8 7 7.3 URRN and ARPT Taggart 7 5 7 6.3 Cybonnet 6 5 6 5.6 Wells 7 7 7 7.0 Templeton 7 8 7 7.3 Taggart 5 5 5 5.0 Cybonnet 4 5 5 4.7 0Wells 6 7 7 6.7 ¹Based on a scale of 0 to 9 where 0 = no symptoms and 9 = no grain formation. Rating Scale: 0 = no damage 1 = 81-90% grain develop 2 = 71-80% grain develop & 96-100% panicles broken from vertical 3 = 61-80% grain develop & 91-95% panicles broken from vertical 4 = 41-60% grain develop & 61-90% panicles broken from vertical 5 = 21-40% grain develop & 31-60% panicles broken from vertical-appearance of parrot-beak 6 = 11-20% grain develop & 10-30% panicles broken from vertical 7 = panicles emerged but totally up right; only 0-10% grain develop 8 = 0-10% panicle emergence, no seed produced 9 = no panicles Performance of Rice Cultivar Taggart in Disease Monitoring Plots

In Table 25, the yield in bushels per acre, or performance of rice cultivar Taggart is compared to various rice cultivars in replicated rice disease monitoring tests located in grower fields in Arkansas in 2008. Column 1 shows the rice variety, columns 2 to 9 show the yield in each location, column 10 shows the mean yield for all locations for each variety and column 11 shows the coefficient of variation (C.V.). C.V. provides an indication of yield variability across environments and lower numbers indicate less variability.

TABLE 25 Craig- Prairie- Prairie- Variety head Desha Lonoke Poinsett DA HA Randolph Woodruff Mean C.V. Taggart 123 125 144 175 208 141 212 146 159 22.0 Bengal 157 162 136 181 194 142 209 175 169 14.9 Bowman 130 131 138 167 200 120 190 149 153 19.3 Catahoula 142 101 123 165 211 132 177 153 151 22.6 Cheniere 153 116 136 169 195 139 225 154 161 21.9 CL 131 145 133 120 150 203 151 202 156 157 19.0 CL 151 125 138 143 184 196 133 184 186 161 17.9 CL 161 139 129 127 158 186 148 186 152 153 15.0 CL 171 AR 136 120 120 150 188 152 189 156 151 17.6 Cocodrie 152 112 112 171 218 156 220 180 165 25.1 Cybonnet 141 140 129 158 208 133 197 143 156 19.2 Francis 145 182 137 191 205 155 226 206 181 17.8 Presidio 134 153 142 151 173 129 200 137 153 15.5 Rondo 118 135 152 147 154 143 200 168 152 16.0 RT XL 723 190 148 175 195 272 170 294 225 209 24.5 Templeton 156 154 145 163 229 149 204 187 173 17.4 Trenasse 115 116 114 155 166 146 190 164 146 19.5 Wells 143 154 144 164 209 175 217 160 171 16.4 Mean 141 137 137 167 202 143 202 166 166 LSD 30.0 20.9 21.1 16.4 49.3 23.5 31.3 19.4 C.V. 13.0 9.4 9.4 6.0 14.7 10.0 9.4 7.1

Tables 26 and 27 show the influence of seeding date on grain yield in bushels per acre and milling yield in % Milled Head Rice: % Total Milled Rice (% HR-% TR) of selected rice varieties conducted at the Rice Research Extension Center (RREC) in 2008.

In Table 26, column 1 shows the variety, columns 2 to 5 show yield for each seeding date and column 6 shows the mean yield for all dates for each variety.

In Table 27, column 1 shows the variety, columns 2 to 5 shows the milling yield for each seeding date and column 6 shows the mean yield for all dates for each variety.

TABLE 26 Grain Yield Variety March 26 April 17 May 19 June 12 Mean Taggart 190 159 150 136 159 Bowman 211 175 147 124 164 Catahoula 181 186 107 127 151 Cheniere 189 175 151 138 163 CL131 187 168 124 143 155 CL151 215 178 119 144 164 CL161 164 156 148  92 140 CL171AR 191 153 115 109 142 CLXL729 226 186 182 180 194 CLXL730 200 192 174 167 183 CLXL745 208 213 170 173 191 CLXP746 247 212 184 176 205 Templeton 207 163 139 127 159 Trenasse 179 171 139 118 152 Wells 185 190 172 128 169 Mean 200 180 149 139 167

TABLE 27 Milling Yield Variety March 26 April 17 May 19 June 12 Mean Taggart 57-68 54-66 57-70 59-71 58-69 Bowman 61-69 59-68 58-68 59-70 59-69 Catahoula 62-69 65-70 58-72 63-73 62-71 Cheniere 61-69 62-69 61-70 57-72 60-70 CL131 64-68 64-68 59-68 60-70 62-69 CL151 59-67 61-68 55-67 58-71 58-68 CL161 63-68 65-70 58-70 65-73 63-70 CL171AR 63-70 61-68 52-70 62-72 60-70 CLXL729 60-68 61-68 58-69 61-72 60-69 CLXL730 60-68 60-68 58-68 58-70 59-69 CLXL745 58-68 58-69 57-70 59-71 58-69 CLXP746 59-68 59-67 57-69 61-72 59-69 Templeton 61-67 61-68 50-70 61-67 57-66 Trenasse 57-66 57-65 54-66 59-70 59-69 Wells 61-69 60-68 52-70 63-73 62-71 Mean 57-69 58-68 57-69 61-71 58-69

Tables 28 and 29 show the influence of seeding date on days from emergence to on-half inch internode elongation and 50% heading for selected rice varieties in seeding date studies conducted at the RREC during 2008.

In Table 28, column 1 shows the variety, columns 2 to 5 show the number of days after emergence for each seeding date and column 6 shows the mean for the number of days after emergence for each variety for all seeding dates. In Table 29, column 1 shows the variety name, columns 2-5 show the days to 50% heading in days after emergence for each seeding date and column 6 shows the mean for the days to 50% heading in days after emergence of each variety for all seeding dates.

TABLE 28 Days to One-Half Inch Internode Elongation March 26 April 17 May 19 June 12 Mean Variety Days After Emergence Taggart 87 78 60 50 69 Bowman 87 80 60 53 70 Catahoula 78 69 47 43 59 Cheniere 80 71 52 48 63 CL131 78 72 52 46 62 CL151 78 69 51 44 61 CL161 CL171AR 83 74 55 48 65 CLXL729 81 53 45 60 CLXL730 78 53 43 58 CLXL745 78 73 52 44 62 CLXP746 81 72 50 43 61 Templeton 87 80 56 49 68 Trenasse 83 73 52 44 63 Wells 84 77 55 50 67 Mean 83 75 55 47 64

TABLE 29 Days to 50% Heading March 26 April 17 May 19 June 12 Mean Variety Days After Emergence Taggart 121 117 96 85 105 Bowman 115 107 95 80 99 Catahoula 113 102 86 79 95 Cheniere 113 102 87 80 96 CL131 107 99 86 77 92 CL151 108 99 85 74 92 CL161 114 106 92 84 99 CL171AR 115 105 90 84 99 CLXL729 109 102 86 78 94 CLXL730 109 101 87 80 94 CLXL745 107 99 83 73 91 CLXP746 109 104 86 77 94 Templeton 118 113 93 82 101 Trenasse 106 99 81 71 89 Wells 115 108 91 82 99 Mean 113 105 90 80 97

Table 30 shows grain yield of rice cultivar Taggart in bushels per acre when influenced by various rates of nitrogen (N) fertilizer. Data were taken in 2008 at three locations in Arkansas. Column 1 shows the fertilizer rate of Nitrogen in pounds per acre and columns 2 to 4 show the grain yield for each location.

TABLE 30 Grain Yield (Bushels Per Acre) for Each Location N Fertilizer Rate LHRF^(z) NEREC RREC  0 77 82 104  60 134 — 152  90 163 171 181 120 182 176 183 150 178 177 194 180 171 173 196 210 — 169 — LSD_((α=0.05)) 13.8 17.8 14.5 C.V. (%) 6.0868 7.4578 5.7269 ^(z)LHRF = Lake Hogue Research Farm, Wiener, AR; NEREC = Northeast Research and Extension Center, Keiser, AR; RREC = Rice Research and Extension Center, Stuttgart, AR. ^(y)A bushel of rice weighs 45 lb.

DEPOSIT INFORMATION

A deposit of the University of Arkansas proprietary Rice Cultivar Taggart disclosed above and recited in the appended claims has been made with the American Type Culture Collection (ATCC), 10801 University Boulevard, Manassas, Va. 20110. The date of deposit was May 12, 2010. The deposit of 2,500 seeds was taken from the same deposit maintained by University of Arkansas, Rice Research and Extension Center since prior to the filing date of this application. All restrictions will be removed upon granting of a patent, and the deposit is intended to meet all of the requirements of 37 C.F.R. §§1.801-1.809. The ATCC Accession Number is PTA-10949. The deposit will be maintained in the depository for a period of thirty years, or five years after the last request, or for the enforceable life of the patent, whichever is longer, and will be replaced as necessary during that period.

While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope. 

What is claimed is:
 1. A seed of rice cultivar Taggart, wherein a representative sample of seed of said cultivar was deposited under ATCC Accession No. PTA-10949.
 2. A rice plant, or a part thereof, produced by growing the seed of claim
 1. 3. A tissue culture produced from the protoplasts or cells from the plant of claim 2, wherein said cells or protoplasts are produced from a plant part selected from the group consisting of leaves, pollen, embryos, cotyledon, hypocotyl, meristematic cells, roots, root tips, pistils, anthers, flowers, stems, glumes and panicles.
 4. A rice plant regenerated from the tissue culture of claim
 3. 5. A method for producing a rice seed, said method comprising crossing two rice plants and harvesting the resultant rice seed, wherein at least one rice plant is the rice plant of claim
 2. 6. A rice seed produced by the method of claim
 5. 7. A rice plant, or a part thereof, produced by growing said seed of claim
 6. 8. The method of claim 7, wherein at least one of said rice plants is transgenic.
 9. A method of producing an herbicide resistant rice plant, wherein said method comprises introducing a gene conferring herbicide resistance into the rice plant of claim
 2. 10. An herbicide resistant rice plant produced by the method of claim 9, wherein the gene confers resistance to an herbicide selected from the group consisting of dicamba, phenoxy proprionic acid, cyclohexone, cyclohexanedione, imidazolinone, sulfonylurea, glyphosate, glufosinate, L-phosphinothricin, triazine and benzonitrile.
 11. A method of producing a pest or insect resistant rice plant, wherein said method comprises introducing a gene conferring pest or insect resistance into the rice plant of claim
 2. 12. A pest or insect resistant rice plant produced by the method of claim
 11. 13. The rice plant of claim 12, wherein the gene encodes a Bacillus thuringiensis endotoxin.
 14. A method of producing a disease resistant rice plant, wherein the method comprises introducing a gene which confers disease resistance into the rice plant of claim
 2. 15. A disease resistant rice plant produced by the method of claim
 14. 16. A method of producing a rice plant with modified fatty acid metabolism or modified carbohydrate metabolism, wherein the method comprises introducing a gene encoding a protein selected from the group consisting of phytase, fructosyltransferase, levansucrase, alpha-amylase, invertase and starch branching enzyme or encoding an antisense of stearyl-ACP desaturase into the rice plant of claim
 2. 17. A rice plant having modified fatty acid metabolism or modified carbohydrate metabolism produced by the method of claim
 16. 18. A method of introducing a desired trait into rice cultivar Taggart wherein the method comprises: (a) crossing a Taggart plant, wherein a representative sample of seed was deposited under ATCC Accession No. PTA-10949, with a plant of another rice cultivar that comprises a desired trait to produce progeny plants wherein the desired trait is selected from the group consisting of male sterility, herbicide resistance, insect resistance, modified fatty acid metabolism, modified carbohydrate metabolism and resistance to bacterial disease, fungal disease or viral disease; (b) selecting one or more progeny plants that have the desired trait to produce selected progeny plants; (c) crossing the selected progeny plants with the Taggart plants to produce backcross progeny plants; (d) selecting for backcross progeny plants that have the desired trait and the physiological and morphological characteristics of rice cultivar Taggart to produce selected backcross progeny plants; and (e) repeating steps (c) and (d) three times to produce selected fourth or higher backcross progeny plants that comprise the desired trait and all of the physiological and morphological characteristics of rice cultivar Taggart as listed in Table
 1. 19. A rice plant produced by the method of claim 18, wherein the plant has the desired trait and all of the physiological and morphological characteristics of rice cultivar Taggart as listed in Table
 1. 20. The rice plant of claim 19, wherein the desired trait is herbicide resistance and the resistance is conferred to an herbicide selected from the group consisting of imidazolinone, sulfonylurea, glyphosate, glufosinate, L-phosphinothricin, triazine and benzonitrile.
 21. The rice plant of claim 19, wherein the desired trait is insect resistance and the insect resistance is conferred by a gene encoding a Bacillus thuringiensis endotoxin.
 22. The plant of claim 19, wherein the desired trait is modified fatty acid metabolism or modified carbohydrate metabolism and said desired trait is conferred by a nucleic acid encoding a protein selected from the group consisting of phytase, fructosyltransferase, levansucrase, alpha-amylase, invertase and starch branching enzyme or encoding an antisense of stearyl-ACP desaturase. 